IE 11 is not supported. For an optimal experience visit our site on another browser.

Who killed Alexander Litvinenko?

Alexander Litvinenko made scandalous accusations that struck right at the heart of the Kremlin. But he ended up in a real-life spy story of political intrigue, conspiracy and murder. Ann Curry reports.
(FILES) A handout image released 20 Nove
Alexander Litvinenko in a London hospital three weeks after he was poisoned by radioactive polonium 210. AFP - Getty Images file

Paul Joyal, Russia expert, security consultant: A message has been communicated to anyone who wants to speak out against the Kremlin: “If you do, no matter who you are, where you are, we will find you and we will silence you—in the most horrible way possible”.

This haunting image of a figure in his hospital bed has become a world famous picture of tortured suffering.

It tells the chilling story of a man who took on the powerful and was silenced. He believed he was fighting for justice and made scandalous accusations that struck right at the heart of the Kremlin. But he ended up in a real-life spy story of political intrigue, conspiracy and murder.

Joyal: It’s just unprecedented.

Disturbing mysteries involving Russia and politics are nothing new: Georgi Markov, the dissident writer was murdered with a poison pellet from an umbrella; Viktor Yushchenko, the Ukranian presidential candidate was poisoned; Paul Khlebnikov, an American business journalist, was gunned down.

But what happened in london may be even more sinister.

Joyal: He was a citizen of the United Kingdom. That has to mean something—that you shall be safe from this type of political retribution.

Six years before that photo was snapped, the same man, Alexander Litvinenko, left his home in Russia to start a fresh life in England.

Joyal: I was fascinated with the guy.

Security consultant Paul Joyal, who is a Russia expert critical of the Kremlin, struck up a friendship with Alexander in visits to London.

Ann Curry, Dateline anchor: And what was your impression?Joyal: He was full of life.  He was strong-willed, obviously. He was very courageous.

In London, Alexander, his wife, and their son were taken under the wing of a Russian tycoon who set them up with a modest home in the suburbs and supported Alexander’s freelance writing career. Marina, a ballroom dance teacher, enrolled their son Anatoly in an international school.

Marina Litvinenko, Alexander's wife: We felt very safe in London, very protected.Curry: Free?Marina Litvinenko: Free. Yes.

November 1, 2006, Marina says her husband “Sasha”, as she called him, planned to spend most of the day in central London and come home to a cozy meal.

Marina Litvinenko:  Sasha just told me he will have some meetings in town.   

But she had no idea that what would happen that day would turn out to be deadly and have far-reaching consequences.

That evening, after dinner, Alexander was suddenly queasy.

Marina Litvinenko: He just first time started to complain he felt not very good.  And I was surprised, because he complained about sickness.Curry: You mean like a severe stomach—Marina Litvinenko: Exactly.  It was every 20 minutes, it was vomit.  He was—everything was very unusual.

It was unusual because she’d eaten the same food as her husband and she felt fine. And Alexander, a 43-year-old health nut who often went for 10-mile runs, rarely got sick.

Assuming he’d come down with the flu, she gave him water and occasionally checked his temperature.

But the following day, his condition became even more troubling.

Marina Litvinenko: And he started to complain about pain in his body, in his stomach.Curry: How much pain was he in?Marina Litvinenko: I think it was very strong.

Marina says her husband was so sick he came to a startling conclusion: that someone had poisoned him.

Marina Litvinenko: Poisoning— "No, Sasha. It’s not possible."Curry: He suspected the second day—Marina Litvinenko: It’s could be—Curry: --that he was poisoned.Marina Litvinenko: Yes.

Marina called for an ambulance and her husband was admitted to the hospital. Doctors immediately suspected he was fighting a gastric flu, but Marina says her husband continued to insist he’d been poisoned.

Curry: Did he say this to the doctors at the hospital?Marina Litvinenko: Yes.Curry: And did they believe him?Marina Litvinenko: No.Curry: They didn’t believe him.Litvinenko: They look at us like crazy people.  You know?Dan McGrory, reporter for the London Times: The doctors threw up their arms and said:  “We don’t know what he’s got.  He’s got something.  This is not explicable by any means that we know.”

Dan McGrory of the London times says it took doctors two weeks to concede Alexander was suffering from some kind of poisoning. So they transferred him to a hospital specializing in toxicology which sent his samples to scientists at a special lab. 

McGrory: And they tested for every possible poison you can think of and tested again and again, and they were coming up with no answers.  All they could tell was this was a man whose entire internal organs were collapsing faster than they’d ever seen.

As his life ebbed away, Alexander continued to issue even more extraordinary claims from his hospital bed. Not only had someone deliberately poisoned him, he said, but it was the work of foreign spies, an assassination conspiracy—and he claimed he knew who was behind it. His allegations soon appeared in the press, and brought British counter terrorism police to his bedside.

McGrory: The police, full of disbelief, had to take seriously the fact that here was a hitherto healthy individual who was now virtually incapacitated. 

They tried to question the now ghost-like figure, but it was frustrating work.

McGrory: The police said, “We interviewed him for three hours” if you ask them how much they got out of that three hours - maybe 5-10 minutes of useful information.  He needed to rest, he couldn’t speak for long. Curry: Did anyone talk about how much he suffered?Joyal: Just that he suffered greatly as you can imagine.Curry: Tremendous pain.Joyal: Mm-hmm (affirms).

Three weeks of hospital care did nothing to stop Alexander’s decline. He lost 30 lbs., put on 30 years... and his hope faded.

Joyal: His words were, “Well, the bastards got me.”

And as he slipped into a coma, he was hooked up to life support.

Marina Litvinenko: His skin changed color. When I saw him last time he was warm, you know.  I could touch him, and I could feel him.  (Crying)

Alexander had endured 22 days of the most intense suffering, but died of heart failure caused by a vicious poison.

It was a testament to his excellent physical shape that this freelance writer survived so long, or else his story might have died with him—the secret of his poisoning taken to his grave.

Just two hours before he passed away scientists at the special lab at last discovered the poison which killed Alexander Litvinenko.

One mystery was solved, but another was about to begin.

What the scientists revealed shocked the world, opened up a trail of intrigue, and started an international murder investigation.

McGrory: The police had to say this was the first in their experience, and it was an act of nuclear terrorism.

After about three weeks of miserable suffering, Alexander Litvinenko lapsed into a coma and died.

But just two hours before he succumbed to the powerful poison, there was unexpected news that left police dumbfounded. Scientists at a special lab had at last discovered the toxin that was killing Alexander. No wonder it took them so long to detect. It was an extremely rare substance called “polonium-210”.

Steve Fowler, radiation specialist: It strikes me as very bizarre that polonium-210 would be used in such a poisoning case. It’s never been used before as far as we know.

Polonium-210 is a radioactive substance sometimes used in industry to reduce static electricity. It can also be used as a trigger for a nuclear bomb.

Fowler: I couldn’t believe that anyone would take the time, the money, the effort and go through the danger of that.

It’s made in nuclear reactors, and is strictly controlled by governments. Only about 100 grams of it are made worldwide each year—perhaps enough to fill a small glass. And it’s very expensive.

Fowler: How much would that cost to have enough polonium-210 to kill Litvinenko in the quantities that they did? It’s probably on the order of $2 million to $3 million.

The scientist says it’s at least a million times more deadly than cyanide, so if inhaled or swallowed, the most minute quantities of polonium-210 can be lethal. Its radioactive particles attack and annihilate the body’s cells.

Fowler: Something about the size of a grain of salt should be enough to kill a person.

Tests showed Alexander Litvinenko had swallowed a lot more than that, perhaps 10 times what was needed to kill him. This had to be a case of murder, police thought.

But why would anyone want to kill him? As they investigated, they found a man of secrets with a dangerous past. He was not just a freelance writer, they discovered. He was a former agent in Russia’s notorious KGB.

Alexander Litvinenko grew up in a small town in the south of the Soviet Union. He was such an accomplished soldier he was called to enlist in the KGB. In the 1980s, he built his reputation as a counter intelligence-officer investigating fraud and busting groups considered anti-Soviet.

But when the Soviet Union collapsed in the early 1990s, so did the KGB, which re-formed as “the FSB”. Alexander headed a crack unit fighting organized crime gangs, say his friends, but he had to take orders from corrupt officers.

Paul Joyal, Russia expert: He saw the moral fabric of the system that he grew up in just disintegrating before his eyes. Ann Curry, Dateline correspondent: You’re describing a moral man.Joyal: He was driven by principles, no question on that.

Joyal wrote:  Daily Report on Russia and the Former Soviet Republics” - political and economic analysis.

Paul Joyal, who wrote a daily newsletter analysis of Russia in the 1990s, says his friend’s principles were severely tested when, in 1997, Alexander was ordered by his FSB officers do something he’d never done in the KGB: to carry out a hit on a man he knew well—a controversial power broker accused of meddling in Kremlin politics, the tycoon Boris Berezovsky.

Boris Berezovsky: Alexander came to me and said, “Boris, it’s unbelievable. I got order to kill you.” “Boris, I know these people. It’s not a joke.”

But instead of killing Berezovsky, Litvinenko did something remarkable for a serving FSB officer.

Joyal: Litvinenko saved his life. He refused to carry out an order. And not only refused to carry it out, but he went public. 

Litvinenko went public in a way never seen before in Russia. He held a TV news conference with fellow officers to denounce the plot. And he exposed in dramatic style what he saw as rampant corruption in the FSB.

He caused a major embarrassment to the FSB and its chief at the time— a man who the world would soon hear a lot about— Vladimir Putin.

At the news conference, while his comrades tried to mask their identities, Alexander did not.

Curry: How exposed did he make himself?Joyal: I thought that the man was out of his mind—being so bold in doing something like this in Moscow to expose himself to—Curry: Death. Joyal: Death.Oleg Kalugin, former KGB general: He betrayed his organization.  He betrayed his colleagues.

Former KGB general Oleg Kalugin who moved to the west in 1995, says Alexander’s perceived betrayal was one possible turning point when he sealed his fate under an old KGB code.

Kalugin: Never forget, never forgive.Curry: That’s the old KGB rule? Kalugin: Absolutely. And they called him traitor, the one who will never be forgotten, will never be forgiven.

Soon after that bold move, Alexander was discharged from the FSB and jailed for nine months.  But after her husband was released from jail, says his wife Marina, the FSB made death threats that were all too real.

Marina Litvinenko: It was very clear message for Sasha.Curry: You’re saying he was warned.Marina Litvinenko: Absolutely.Curry: By people in the FSB that he was in danger.Marina Litvinenko: Absolutely.

And, she says, the threats got even worse.

Curry: You’re saying there were warnings that not only was his life in danger, but—Marina Litvinenko: Exactly.Curry: --your life was in danger?Marina Litvinenko: Exactly.Curry: And your son’s life was in danger?Litvinenko: Exactly.

It seemed so serious that Alexander made a desperate decision in the year 2000. He used a fake passport and escaped to England where he, his wife and son were eventually given political asylum.

Then Alexander Litvinenko unleashed a firestorm. In his new London home, he wrote inflammatory books and articles accusing the Russian government of mass murder, of war-mongering, and he wrote personal attacks against President Putin, who was videotaped lifting the shirt of a boy and kissing him.

Curry: He wrote that Putin was a pedophile. He wrote that Putin provided cover for drug trafficking. He wrote that the Kremlin staged the apartment bombing that killed 300 people in Russia to justify—what turned into the second war on Chechnya.Joyal: He was saying things that were just almost inconceivable to people there. He was engaged in slander of the president as they would see it.  He held nothing back. This man was absolutely hated. 

If Alexander had enemies before, he had even more now. Shipment of his book “Blowing Up Russia” was reportedly intercepted on the way to book launch in Moscow.

On a Russian Special Forces firing range, Alexander’s face became the target. And he was worried that others were taking aim at him.

His wife Marina became concerned.

Curry: As he was writing, you felt it was dangerous for him—Marina Litvinenko: Yes.Curry: —you were nervous—Marina Litvinenko: Of course.Curry: --as he was writing, that he was putting himself at risk.Marina Litvinenko: Exactly. I ask him, “Are you sure you should do it in this way?”  He said yes. 

But living in England, her husband believed he was untouchable and safe from anyone who might want to get back at him for speaking out against the Kremlin.

Curry: So, when you became British citizens, you felt this cloak of protection—Marina Litvinenko: More and more, yes.

But that cloak was torn when Alexander began investigating the recent death of one of his friends in Moscow. 

Just three weeks before he was poisoned, an investigative reporter— who like Alexander, was a strident Kremlin critic— was murdered.

Joyal: She was shot—twice in the chest, once in the shoulder. And as she lay on the ground, just to make sure—an additional shot was delivered to her head.

It was while Alexander was investigating his friend’s murder that he too was killed.

Then from beyond the grave, in a remarkable move, Litvinenko would name the man he believed had silenced him, the same man he held responsible for his friend’s death.

In a statement read by a friend Litvinenko blamed Russia’s President Vladimir Putin no less - for his murder, 

“You may succeed in silencing one man but the howl of protest from around the world will reverberate, Mr. Putin, in your ears for the rest of your life. May God forgive you for what you have done, not only to me but to beloved Russia and its people.

It seemed a preposterous allegation, but the police investigation was about to take an astonishing turn that would leave the world wondering.

Police were about to retrace Alexander Litvinenko’s last footsteps and make even more amazing discoveries.

Dan McGrory, reporter for The London Times: And from there the polonium trail on the day of November 1st begins to take on quite a sinister and ominous trait.

British police investigating the murder of Alexander Litvinenko suddenly got a critical break in their case.

The polonium-210, they discovered, was easy to trace and had left a glowing radioactive trail.

If they followed Litvinenko’s movements on the day he got sick, they figured, they might be able to determine where he was murdered. And, by whom.

London Times reporter Dan McGrory followed the investigation.

Dan McGrory, London Times reporter: The police are certain in their own minds that Litvinenko was poisoned on November 1st.

So police started where Litvinenko started when he set off from home that Wednesday.

On the morning of November 1st, Litvinenko took a bus to central London for a series of meetings. But police found no traces of polonium on the bus... or on his bus ticket.

McGrory: We know that he went to a shop and he browsed around the shop and he bought a bottle of water and he picked up a newspaper and there was no polonium ever found in that shop. 

But just after 3 p.m., when he came to this sushi restaurant, the polonium trail suddenly lit up. There is where Litvinenko had lunch with a well-connected Italian contact.

Mario Scaramella, nuclear waste and security consultant: He was a perfectly normal.

Mario Scaramella, a consultant in nuclear waste and security, told "Dateline" he had flown in to London from Italy on business. He had secret information about Litvinenko’s friend, the murdered investigative reporter. So they slipped into the sushi restaurant for some privacy.

Scaramella: We arrived in this place and he took a box with some sushi. 

Scaramella says since it was mid afternoon and he’d already eaten, he bought just a bottle of water.

Scaramella: And we went downstairs. And we sit near a table. Alone.  No other people with us.

He handed Litvinenko e-mails from a secret Russian source. They appeared to be a kind of hit list that outlined a conspiracy.

Sure enough, one of the names in the document was that of the murdered journalist. But so was Litvinenko’s, Scaramella’s, and others too.

All those listed were apparently targeted for elimination by a shadowy Russian group of ex-KGB agents called “Dignity and Honor”.

Oleg Kalugin, ex-KGB: Dignity and Honor—Ann Curry, Dateline correspondent: Exists?Kalugin: —has been in existence for at least 10 years. 

Former KGB general Oleg Kalugin, says “Dignity and Honor” is a brotherhood of ex-secret agents nostalgic for hard-line Soviet ways. He says the group hunts down perceived traitors and shows no mercy.

Curry: Do they assassinate people?Kalugin: Well, in terms of a willingness to punish traitors, well, they stated it clearly in some of the public releases they made over the years.Curry: That they want to punish traitors?Kalugin: Absolutely.Curry: And—Kalugin: That’s what—Curry: —Alexander Litvinenko would have been considered a traitor?Kalugin: Absolutely he was a traitor. So was I and a number of others. They have a list.  Curry: Do you think Dignity and Honor could have killed Alexander Litvinenko?Kalugin: They would love to kill him.

Was “Dignity and Honor” somehow involved in killing Litvinenko? Police would investigate further but for now they focused on Scaramella, who became their first suspect. After all, the radioactive poison was found in the restaurant where Scaramella, a nuclear waste consultant, met with Litvinenko.

Could it be that the Italian got hold of polonium-210, which is made in nuclear reactors, and poisoned Litvinenko in the sushi restaurant?

Perhaps, but police continued to follow the radioactive poison from Litvinenko’s day of meetings.

McGrory: And from there, the polonium trail on the day of November 1st begins to take on quite a sinister and ominous trait.

Sometime around 4:15 p.m. that day Litvinenko came to the office of the tycoon Boris Berezovsky, who by now was also living in London.

Berezovsky told "Dateline" Litvinenko came to his office immediately after his sushi lunch to warn him. It turned out Berezovsky too was named in the hit list.

Boris Berezovsky: He call me and said “Boris, I have very important papers to give you.” And he came to my office and he copy these papers in the office and gave it to me.

But after police found traces of polonium at his office, Berezovsky became the second suspect in this murder case.

McGrory: And the police went to him, and they asked the question, “Did you have any role to play in this?”

In Russia, Berezovsky had been accused of criminal corruption. And the media there said he was ruthless enough to murder the man who saved his life and try to pin the blame on those in the Kremlin.

Were they right? Or was there something else?

Though Berezovsky had paid for Litvinenko’s house and living expenses since his escape to England, he had recently cut the funding. Was there bad blood between the two?

Whatever the truth, the mystery deepened as police investigated the next stop Litvinenko made that day, sometime around 5 p.m.

Here in the upscale Millenium Hotel Litvinenko met two well-heeled acquaintances, former KGB agent Andrei Lugovoi and his business partner. Litvinenko apparently was impressed with their success.

McGrory: He was very envious of the fact that former colleagues of his had all done extremely well financially and he had complained to a number of people endlessly that he was struggling financially.

In an exclusive interview with "Dateline," Lugovoi said he’d flown in from Moscow to watch an international soccer match. He said he was also using the trip to drum up business for his security company, which specializes in bodyguard training.

He and his business partner, who’d arrived from Germany, said they wanted Litvinenko to broker business deals with British companies.

Lugovoi, via a translator: He put me in contact with serious companies with good reputations around the world. He was the middle man and was interested in picking up a big commission…

In the hotel bar, Lugovoi and his partner apparently ordered shots of gin while Litvinenko, who never drank, sipped a cup of tea.

Nothing seemed unusual when, sometime after six, the meeting broke up in time for the Russian’s soccer game.

McGrory: So when Lugovoi and others set off to the Stadium, Litvinenko got a lift, went back to his home, and it was when he got back later in the evening that he showed the first signs of physical distress, he began to feel ill. 

But after police discovered polonium-210 in the bar where they sat with Litvinenko, Lugovoi and his business partner soon became suspects number three and four.

Was the ex-KGB agent Lugovoi perhaps linked to that shadowy group of former KGB agents called “Dignity and Honor”?

Police found themselves with a baffling case, extraordianry evidence, and an array of possible suspects including an Italian nuclear waste consultant, the tycoon Boris Berezovsky, and an ex-KGB agent and his business partner.

But as they closed in on who they thought killed Alexander Litvinenko, they discovered red flags, more compelling evidence and one critical fact about the deadly poison.

Polonium-210 is a strictly controlled substance, produced mainly in one country.

Steve Fowler, Radiation expert: Russia is believed to be the largest producer of polonium-210.

Which of their suspects might have access to the radioactive poison, police wondered?

Joyal: This was a poison constructed for this murder. This is not a mere criminal act.

What started as a horrific killing, became a radioactive trail, and then, nuclear terror in the heart of London.

“Somebody has apparently been deliberately poisoned,” says Doctor Jill Meara, Deputy Director, Health Protection Agency, Radiation Protection.

As holiday season approached, health officials made public the trail of deadly polonium.

Dan McGrory, reporter the Times of London: The police had to say this was an act of nuclear terrorism.

And there was panic.

McGrory: Suddenly London went into a frenzy of polonium poisoning. And so people were suddenly rushing to their doctors; instead of asking for flu jabs and complaining of usual aches and pains and flu—were claiming they were suffering from polonium poisoning.

British Police had never faced anything like this before. The were trying to unravel an international mystery... and get answers for a wife and a son.

Ann Curry, Dateline anchor: You wanna know what happened to your husband.Marina Litvinenko: Exactly.  Yes.

By following the trail of polonium-210 police had narrowed their search down to four main suspects, an Italian nuclear waste consultant, a Russian tycoon, and a former KGB agent and his business partner, who all met Alexander Litvinenko on the day he was poisoned.

London times reporter Dan McGrory is covering the police investigation.

McGrory: Their original idea was that it happened in the sushi bar…

Police took a hard look at the Italian, Mario Scaramella.

Sure, he been in the sushi restaurant where the polonium was discovered.

But there were reportedly no traces discovered at the table where he and Litvinenko had lunch. So Scaramella was dismissed as a suspect. 

Mario Scaramella: Absolutely not.  He was a friend.

Next, while the polonium trail showed up in the offices of their second suspect, Boris Berezovsky, the radioactive agent wasn’t found anywhere else where the tycoon had been.

As for a motive, Berezovsky said there was no bad blood between him and Litvinenko. What’s more, they were allies against the Kremlin, and Berezovsky apparently had no reason to have Litvinenko murdered.

So police also dismissed him as a suspect.

Berezovsky: I am not involved to his terrible murder.McGrory: He claimed that it was a dirty tricks campaign by his enemies in the Kremlin, to try and blacken his name.

But what about the other two men - the third and fourth suspects? When police took a long hard look at the movements of Andrei Lugovoi and his partner, they found an astonishing pattern.

McGrory: The police had to go back and check all the places that these men had stayed in, the hotels they’d visited, the bars, the restaurants… and in each of the places they had been, remarkably, they found traces of polonium-210.

Police found polonium on planes Lugovoi and his partner took from Moscow and Germany, in three London hotels where they stayed, in that sushi restaurant where they dined with Litvinenko two weeks before he met with the Italian, Scaramella.

It turned out Lugovoi and his partner had visited the offices of Boris Berezovsky, where the polonium trail led.

And polonium showed up in a seat in the soccer stadium where Lugovoi watched the game.

But police got an off-the-charts reading of polonium-210 in the bar of that upscale hotel where Litvinenko sat with Lugovoi and his partner, drinking tea.

Some 130 people also tested positive for traces of the radioactive substance. So far no one has gotten sick but  nearly all of them had been in the places where Lugovoi and his partner had been.

McGrory: We thought the days of cloak and dagger and Cold War and Russian espionage had gone.

While Scotland Yard has not made any official comments on this case, police and intelligence sources paint a detailed picture of how investigators believe the murder happened: They think Lugovoi and his partner brought the polonium from Moscow to London.  Whether in a liquid or carried as a fine powder, no airport security device could detect the radioactive poison. Then fatal dose was secretly administered and the men returned to Moscow.

Steve Fowler, radiation expert: The amount of polonium-210 that is suspected of being used indicated that the people that did this really intended it to be a lethal dose with no questions asked.

It was in the Millenium Hotel where police  believe the murder was executed.

McGrory: The police are convinced it was in that bar that the poison was given to him - and the most likely explanation is that it was in a pot of tea.

The alleged plot to poison Litvinenko’s tea suggests a scheme of such detailed planning police believe Lugovoi and his partner might be just two members of a bigger assassination squad.

They want to question a possible accomplice, a mysterious figure described as a tall and muscular man with Asian features. Captured on security cameras in a London airport, he apparently traveled on three fake passports and then disappeared.

Lugovoi (through a translator): It’s all a lie. A lie created and spread in the West. I want to stress it’s all a lie.

Lugovoi and his business partner dismiss all the accusations as outrageous allegations. They admit meeting with Litvinenko but say they had nothing to do with polonium-210 or murder in the hotel bar.

McGrory: “If Litvinenko had been poisoned in that bar, then it must have either been somebody posing as a barman or a member of staff.” That was their explanation to the police for what happened in the Millennium Hotel.

In fact, Lugovoi and his partner didn’t try to leave London after Litvinenko was rushed to the hospital; they say they contacted British authorities when they heard he was poisoned; and they say they too are victims of polonium contamination and had to be treated at a Moscow hospital.

Now back in Moscow, they say they are prepared to return to London if they are charged by british prosecutors.

Lugovoi and his partner deny being members of the group of ex-KGB agents called “Dignity and Honor.”

They say someone could have framed them  for Litvinenko’s murder by planting polonium-210 on them.

Joyal: We cannot assume that how this unfolded was the way it was planned or that the people involved actually knew the consequences of the material they were dealing with. 

British authorities apparently have no evidence Lugovoi and his partner had any motive to murder Alexander Litvinenko.

But if the ex-KGB man and his partner were involved, as the polonium trail suggests, police believe the men could have been acting on orders from someone else... someone who could obtain polonium 210.

Joyal: When someone dies from a state-controlled substance, a substance that is manufactured in—in state controlled facilities, where does it come from?

As the trail of polonium leads to Moscow, the biggest question hanging over the murder now is whether anyone in the Kremlin had a hand in it.

The mystery of the man who became known as “the Russian spy” continues to intrigue people all  over the world. There are daily fragments in the media, books to be published, and maybe even a hollywood movie.

And behind it all is one central question: does the trail of polonium in London lead all the way to the Kremlin in Moscow? Some think it must. How else would someone get their hands on polonium-210, a state controlled substance?

Paul Joyal: It’s clear-cut.  It has to be a state-run or a state-managed operation.

Before he died, Alexander Litvinenko gave his own answers.

Dan McGrory, Times reporter: He had absolutely no doubt that he had been murdered on the orders of the Kremlin, and that this entire plot had begun in Moscow, and that it was settling scores for him leaving the intelligence service and betraying President Putin.

British prosecutors are now reportedly examining evidence that the Russian government conspired to use a regulated radioactive substance to murder Alexander Litvinenko.

But while that might seem unbelievable, Litvinenko’s friend Paul Joyal argues—and many Russia observers agree—a disturbing number of Kremlin opponents have been killed in recent years—crimes never solved.

Not only the investigative journalist, the friend of Litvinenko, but Russian congressmen and a congresswoman, and others who investigated government business.

Joyal: You have a whole series of cases where journalists have been murdered. People being told to muzzle their criticism of the government.  This is a pattern.  It’s a pattern.

Marina Litvinenko believes her husband is dead because he spoke out.

Marina Litvinenko: They said, what he did, it’s not forgiven.Ann Curry, Dateline correspondent: They said—Marina Litvinenko: Yes exactly.Curry: --it’s not forgiven what you have said about the Kremlin, about Vladimir Putin—Litvinenko: Yes and about his open conference in 1998.Curry: His news conference in which he outed the FSB.Marina Litvinenko: Absolutely—Curry: If that’s true then, if the government of the Kremlin had anything to do with Sasha’s death, does that mean that the order comes from the top?Marina Litvinenko: It could be, yes. Curry: Likely?Marina Litvinenko: Yes. Curry: Almost immediately upon hearing that he had been poisoned, you began to suspect that this went all the way to the Kremlin.  Joyal: Absolutely.Curry: What are the chances this goes all the way to the top?Joyal: Did Putin order it? We can’t say that.  But I would find it hard to believe that this information, whatever it may be, has not filtered its way up to the top.Curry: Why would the Kremlin be involved in something that has so many fingerprints that point to the Kremlin? Why not just a simple bullet in the back of the head?Joyal: Death could have been unknown, natural causes, with no fingerprints attached.

Joyal believes whoever planned the murder deliberately used a radioactive poison produced mainly in Russia to send a strong message.

Joyal: The benefit from their standpoint is, “We are letting everyone know that we will inflict a horrible death, a public, horrible death on those that speak out against us.”

The Russian government strongly denies any involvement in the murder of Alexander Litvinenko.

Dmitry Peskov, spokesman for President Putin: Russia gets blamed for every sin in this world.

A spokesman for President Putin describes allegations against the Kremlin as absurd.

Peskov: No.  No.  No, it is unthinkable.  This is unimaginable that someone in Russia, official Russia in Kremlin or President Putin himself can be somehow linked to any murder of any man.

Dmitry Peskov insists no polonium-210 has gone missing from Russian stockpiles.

Peskov:It is completely impossible to guarantee—for example, that this polonium was not from the United States or that this polonium is not from France or is not from Ireland or is not from Russia. This is why we’re having this investigation.

He told "Dateline" the killing was most likely carried out by enemies of the state who want to ruin Russia’s name.

And at a recent news conference, Russia’s president himself gave another side of Alexander Litvinenko’s story not usually told in Western media.

He recalled that 1998 press conference in which Litvinenko took on the FSB, after which he was jailed.

Putin (from press conference): Alexander Litvinenko was dismissed from the Russian security services. He was involved in criminal proceedings for abusing his position, beating citizens during arrests and for stealing explosives.

Putin played down Litvinenko as a small fish who had no access to state secrets and posed no threat to Russia. He added only a court could decide who was guilty of his murder.

The Russian government has launched its own investigation into the death of Alexander Litvinenko, a process that could take a long time and could keep key witnesses away from British prosecutors.

The Kremlin insists it wants to get to the bottom of this gruesome killing and a few days ago Russian prosecutors arrived in London to interview witnesses. Friends of Litvinenko say that is just a ploy to buy time and preserve a political murder as a mystery.

Joyal: As long as there is a possible deniability, it’ll go away in time.  Maybe not this week.  Maybe not next week.  But if you just hang in there and deny, it will be forgotten.  And there’s nothing anyone can do.

For now, Marina Litvinenko is doing what she can. She has written to President Putin challenging him to help bring her husband’s killers to justice. But she is still struggling to make sense of losing the man she so loved.

Marina Litvinenko: I just feel he’s here I was a very happy woman with him. I told him, “Sasha, we have plenty  time together to spend in our life.” I couldn’t imagine that it will finish so soon.

There was some collateral damage in the poisoning of Alexander Litvinenko. British health officials say about 130 people probably had direct contact with polonium-210 and that 16 of them got a dose large enough to slightly increase their risk of developing cancer.

We deeply regret that Dan McGrory sadly passed away in February. And in another (much more) mysterious incident, four days after our story first aired, another interviewee, Paul Joyal, was shot just outside his home in Maryland. The crime remains unsolved.