Samantha Lewthwaite, known as "Sherafiya," is thought to be a key member of al Shabaab, the Somalia-based militant group that has claimed responsibility for the deadly Nairobi mall siege.
She is wanted by Kenya on charges of being in possession of explosives and conspiracy to commit a felony dating back to December 2011, according to Interpol.
Circulated to all 190 Interpol member countries, the Red Notice is one of the international crime fighting organization's most powerful tools in tracking international fugitives.
"By requesting an Interpol Red Notice, Kenya has activated a global 'tripwire' for this fugitive," said Interpol Secretary General Ronald K. Noble.
While the Interpol notice does not specifically cite the mall attacks, Lewthwaite was mentioned on al Shabaab’s Twitter feed before the post was taken down late Sunday.
It is not the first time Lewthwaite has been linked to attacks in Kenya, where police believe she was part of a thwarted attack on hotels in the holiday resort in Mombasa, planned for Christmas 2011.
Lewthwaite hails from Banbridge, a small town around 30 miles south of Belfast in Northern Ireland.
She is a Muslim convert whose husband Germaine Lindsay was one of three suicide bombers responsible for the July 7, 2005 London bombings.
Her mother, Christine Allen, is widely reported to have met her father, Andy Lewthwaite, while he was serving as a British soldier in the 1970s in Northern Ireland at the height of the time known as "The Troubles."
As a child, she lived in Banbridge for two years, with her parents and older siblings Sabrina and brother John, attending a local primary school, according to the Belfast Telegraph newspaper.
Her grandmother Elizabeth Allen, who still lives near the town, told the paper that she now wears a panic alarm in case Lewthwaite reappears.
“I’ve been told by Special Branch [police officers] to contact them immediately if anything happens," she said.
After her father left the army, they returned to the British mainland, settling in Aylesbury, a small town north of London, where family friends describe her as a "jolly girl."
Raj Khan, a local councilor who has known Samantha for years said he finds it hard to reconcile the woman who he sees on the news, with the girl he once knew.
"She was a jolly child, and a really good person," he told NBC News. “She was an innocent young person. She would do anything to help other people, she was a very good human being."
He added that he fears his old friend was being demonized and that he will only pass judgment on the girl he knew if she is charged with terrorist activity.
"She was not strong-headed," he said. "That's why I find it absolutely amazing that she is supposed to be [involved in] an international criminal terrorist organization."
Family friend Niknam Hussain added that she was not born into Islam, but had become interested in it after befriending a local Muslim family.
“They were a nice normal Muslim family of Pakistani origin, nothing radical about them in the slightest," he told NBC News. "The father was a pious man who helped out in the local mosque, but they were not extreme at all. They still aren't."
He added that Samantha had befriended two daughters, of a similar age and spent a lot of time at the family's home after her parents split in 1995, according to Britain's, Daily Mail.
At around the age of 15, she had asked to become a Muslim.
"It was entirely her decision," Hussain added. "She was not pressured or cajoled into anything. She was very keen to do something herself and as far as I know her family supported her decision and the Muslim family helped to facilitate this.
"Quite how and where she became radicalized, I don't know, but it certainly wasn't here. The family still goes to the mosque but they are normal members of society. The brothers are both mechanics and the daughters who were friends with Samantha are now housewives.”
In an interview with Britain's The Sun tabloid, Lewthwaite said she met suicide bomber and fellow Muslim convert, Germaine Lindsay in an online chat room when she was 17 and the pair were married three years later.
After the coordinated suicide attacks which killed 52 and injured over 700 on July 7, 2005, she publicly denounced her 20-year-old husband.
"She seemed genuine," Hussain said. "She went back to her family so I think they had a very strong relationship."
But then she disappeared.
Nothing was known of her whereabouts until earlier this year when it emerged that she had gone on the run after police foiled a plot to blow up Western tourist targets near the Kenyan resort of Mombassa.
When British national Jermaine Grant and Kenyan Fouad Manswab were arrested in December 2011, police allegedly found ingredients identical to those used in the London bombings, according to Britain's Daily Telegraph.
Under questioning, both men claimed they were acting under the direction of Lewthwaite who somehow managed to avoid arrest.
So fearful of her influence were Kenyan authorities that when her accused co-conspirator originally came to trial, the case was moved to a high security court because of a new "security threat," Jacob Ondari, the deputy public prosecutor, told Mombasa magistrates’ according to Kenya’s The Nation newspaper.
He was due in court again on Monday, but it was unclear if the trial started again due to the hostage crisis.
"We know that Fouad is in touch with Samantha Lewthwaite, and they were planning to rescue their accomplice," Ondari told reporters.
But in a March 2012 interview with The Sun, Lewthwaite's father Andy denied that she would have anything to do with the plot.
“Samantha would not be involved in anything to do with terrorism. She was badly affected by what happened before and would have nothing to do with it. I am sure of that,” he told them, although he admitted he hadn't heard from his daughter for some time.
Since then Lewthwaite has been on the run for 15 months and it was thought that she was in Tanzania or Somalia. British and Kenyan media are now reporting that she is a suspect in the Westgate Mall attack in Nairobi.