As British Prime Minister David Cameron gathered world leaders in London Thursday for a summit aimed at cracking down on corruption, investigative journalists, authors and activists are highlighting that the world's super-rich park their cash — and in some cases "dirty money" — in the city.
LONDON — Motorized group tours of London's famous landmarks are almost as common as the city's iconic red double-decker buses.
One recently inaugurated trek through the British capital isn't trying to show off the country's historical treasures, however.
Instead, Kleptocracy Tours aims to shed light on where the world's rich and powerful stash their billions.
With some high-end properties in and around London running at the tens of millions of dollars, the city is well-placed to launder illicit funds or park money that is being hidden from tax authorities. In fact, British officials estimate that around $173 billion in laundered money entering the country every year is whitewashed via bricks and mortar — with much of it ending up in the country's capital.
"As Yuri Gagarin said on this day 55 years ago, 'Poehali!' — let's get rolling," booms former investment banker turned anti-corruption campaigner Roman Borisovich at the start of the most recent tour.
It's an apt opening quote for the impeccably dressed Muscovite who speaks English with a rich Russian accent. Gargarin the cosmonaut became the first human to enter space 55 years ago. The qualities required for such a feat — fearlessness, determination and showmanship — also apply to the task of taking on some of the world's richest and most powerful.
With a U.K. government-led summit on anti-corruption attracting world leaders including Secretary of State John Kerry to London on Thursday, Borisovich's tours could hardly be better timed.
The bus starts in Whitehall, the seat of British government next to the River Thames, and takes in some of London's poshest neighborhoods.
Participants are handed a Monopoly-style diagram of the city, with prominent international families and government figures dotted around the schematic map. The names on the board range from former Middle Eastern presidents and monarchs to African leaders-for-life and cronies of Russian President Vladimir Putin.
Borisovich, who founded the Committee for Legislation Against Moneylaundering in Property by Kleptocrats (ClampK), claims 1-in-10 of the plush mansions surrounding the iconic British Houses of Parliament in Westminster are owned by an overseas-registered corporation. That company might itself be owned by another corporation, and another after that, making tracing the real owner very hard, he said.
Investigative journalists, authors and activists also act as tour guides, detailing the publicly known financial dealings of many of the figures on the map. They speak very carefully, clearly aware of the country's strict libel laws.
The tour features five-story mansions, former underground train stations and vast commercial properties.
Just around the corner from the Harrods and Harvey Nichols department stores in the well-heeled borough of Knightsbridge is a multi-story mansion belonging to the son of a deposed Middle Eastern president, according to one of the guides.
Close by, a world-famous, high-end hotel is said to be owned by a Middle Eastern monarch. A luxury apartment belonging to a powerful Russian official is worth 80 times his annual income, they said.
Why do so many of the world's super-rich park their cash in London? Because it's easy and it works, according to Borisovich.
"This is a place where a company can come, buy a luxurious piece of property, and just put down the name of its director without telling us who is behind it," he said.
"Everything else helps in London as well ... I mean this is the best ownership legislation, robust, tested, it's a cultural center, education center. But first and foremost is the ease with which dirty money can come here and anonymously buy anything," he added.
The kleptocracy tour debuted in February before the revelations of the Panama Papers — a trove of leaked documents that shed light on a network of law firms and banks that offer financial secrecy and investments in low-tax regimes.
Growing interest in the tour's outings feeds on the perception that many of the world's richest are avoiding paying their fair due in taxes.
According to watchdog Group Transparency International, companies based in British territories overseas —former British colonies — own 36,000 homes in London.
"Were all those houses bought using illicit money? Probably not, but the rules create an environment where the corrupt can easily hide," said Rachel Davies, the group's head of U.K. advocacy and research.
"What's striking about the Panama Papers is the fact that it really blew the lid off the U.K. being involved in these issues," she said. "Half of the companies involved in the Panama Papers are based in British overseas territories, almost 2,000 of the professional enablers, accountants, [real] estate agents, that were working with the Panama firm were based in the U.K."
"The U.K., unfortunately, is complicit in the laundering of corrupt funds," she added.
Borisovich said the Panama Papers leak was great news.
"We couldn't have wished for anything better ... We need Mossack Fonseca we need these leaks," he said, referring to the Panamanian law firm at the center of the leak.
HM Revenue and Customs, which is responsible for the collection of taxes, and the Treasury, which executes government's public finance policy, did not respond to NBC News' questions on whether the government was considering tightening rules governing the real-estate sector.