Built in the style of a French chateau, with a palatial roofline rising high over the River Thames, Whitehall Court is one of Britain's grandest private buildings.
The imposing Victorian pile, which was once the HQ of the Secret Intelligence Services, has also provided homes to a host of famous artists and writers — including George Bernard Shaw and Oscar Wilde — society figures, political grandees, and two Prime Ministers, Alec Douglas-Home and William Ewart Gladstone.
Today, three-bedroomed flats there fetch upwards of £5 million ($9.7M) and enjoy sweeping balcony views of the river and Big Ben. So imagine, if you will, the grandeur of two such properties, knocked together to create one vast apartment, reports Daily Mail.
Actually, we don't need to imagine. For on the seventh floor of Whitehall Court, a man called Igor Shuvalov, and his wife, Olga, have done exactly this.
Their six-bedroom pied-a-terre covers more than 5,300 square feet, and contains a dining room with two fireplaces, a sitting room with chandeliers and a grand piano, and acres of marble. In 2014, they paid £11.4 million ($22.2M) for it, in cold, hard cash.
So far, so normal, in London's turbo-charged luxury property market. But Shuvalov — who stumped up another £800,000 ($1.5M) in stamp duty — was no ordinary mega-rich foreign buyer.
Instead, he happens to be a close chum of Russian President Vladimir Putin. By day, the career politician actually works as his country's First Deputy Prime Minister on a taxable salary which, at the time he was dropping upwards of £12 million ($23.4M) on the London bolthole, was a mere £112,000 ($218,970).
Strangely, in asset declaration lists which the country's politicians are required to publish, in the year he bought the flats he listed his and Olga's entire net worth as a mere £634,000 ($1.2M).
Quite how a 51-year-old Kremlin insider — on paper Russia's third-highest-ranking politician — came to afford a property worth many times more than his annual income is anyone's guess.
What we do know, however, is that he went to great lengths to purchase his high-rise hideaway, a stroll from 10 Downing Street, very discreetly indeed. The transaction was channelled via a tax haven to Sova Real Estate LLC, an opaque company listed in Shuvalov's home country. That prevented his name from appearing on Land Registry Records.
However, the politician's connection to Whitehall Court was uncovered only thanks to Russia's opposition leader, Alexei Navalny, who accused Shuvalov of having "hidden the flat behind anonymous offshores".
In response, a Kremlin spokesman did not deny that Shuvalov owned the London flat, but said that he "[did] not see anything new" in Navalny's disclosure of its existence.
Chateau Shuvalov was the first of many intriguing stops on an eye-opening bus trip around Central London staged this week by ClampK, an organisation which lobbies against laws that allow the British property market to be used as a vehicle for money laundering.
The 'Kleptocracy Tour', attended by politicians and anti-corruption groups, took in some of the capital's grandest addresses, many of which have in recent years been secretly hoovered up by foreign buyers whose wealth was acquired in dubious — or in some instances criminal — circumstances.
The tour was hosted by Roman Borisovich, a Moscow-born financial expert forced to flee his home country in 2012 after he began campaigning against endemic corruption by Vladimir Putin and his cronies.
Thanks to recent events in Salisbury, our trip had an entirely Russian theme. For with Theresa May promising to respond to the Wiltshire poisoning by freezing the assets of Kremlin associates, the flow of so-called "dirty money" from Moscow to the UK is once more at the top of the news agenda.
"London at the moment is the most corrupt place on Earth," is how Roman Borisovich puts it. "There is more dirty money in the real estate market here, per square foot, than anywhere else on the planet. Once a Russian gets their cash here, they know it is safe and can be kept secret. You have the rule of law. You are a global financial centre, with close ties to great tax havens. You have great schools and universities for their kids, and PR firms prepared to launder their reputation."
Though Britain has expelled a number of Russian diplomats, following the poisoning of former double agent Sergei Skripal and his daughter earlier this month, it's widely thought that the most effective way to exert pressure on the Kremlin would be to target UK assets owned by Putin's cronies, many of which were acquired in highly opaque circumstances. And that's where Mr Borisovich's tour comes in.
The three-hour trip took in some of "Londongrad's" most desirable addresses, including — to cite one colourful example — Eaton Square in Belgravia, where a community of minor royals, aristocrats and prime ministers, including Neville Chamberlain and Stanley Baldwin, once lived.
Having in the later years of the 20th century become home to pop stars and Hollywood royalty (including Sean Connery, Vivien Leigh, Rex Harrison and Barry Gibb), it's now known in the trade as "Red Square" thanks to its recent colonisation by wealthy Russians close to the Kremlin.
One of the square's largest properties is a stucco-fronted Regency mansion, adorned with marble pillars, spread over five storeys on a desirable corner plot, and currently swathed in scaffolding. Its owner is a businessman named Andrey Goncharenko.
He is an obscure figure, even by the standards of wealthy Russians. A senior, but not top, executive at the state oil company Gazprom — specifically first deputy director general of GazpromInvest, the firm's investment arm — he boasted no obvious source of vast wealth, and his name had never appeared in so-called "rich lists". In 2014, he suddenly embarked on a massive UK property buying binge, snapping up a staggering quarter of a billion pounds worth of London real estate.
The spree included not just the Eaton Square pile — a snip at £15 million ($29.3M) — but also Hanover Lodge, a Grade-II listed Regency mansion next to Regent's Park (which at £120 million ($234.6M) was the most expensive townhouse ever sold in the UK), 50 St James Street in Mayfair (£70 million) ($136.8M) and a mansion in Lyndhurst Road, Hampstead, which he bought for £41 million ($80.1M) using an offshore firm registered in Gibraltar.
It was unclear why one man would need four family homes in London, or how he might have obtained such wealth while remaining firmly below the radar.
Goncharenko's lawyers said at the time that he'd acquired his cash through road haulage and forestry, and had made "significant profit" in the Nineties.
Like most wealthy Russians, of course, he was also well-connected to the Kremlin.
Impeccably connected, in fact, thanks to a close business relationship with a billionaire called Boris Rotenberg (with whom he is partners in a large property firm). Rotenberg, who happens to be Putin's former judo partner, has previously seen how global events can hit wealthy Russians in the pocket.
He had U.S. and EU sanctions and travel bans imposed on him following Russia's annexation of Crimea in 2014, the very year Goncharenko went on his property-buying bonanza.
Despite the occasional legal problem, there are many reasons why a certain sort of wealthy Russian likes to spend at least a portion of their time in London.
In addition to the restaurants, luxury car dealerships and designer boutiques of Mayfair, Knightsbridge and "Chelski", our capital city provides ready access to financial markets, along with (crucially) some of the world's most sought-after educational establishments.
Today, the Independent Schools Council claims more overseas pupils come through our private system from Russia than from any other country, with the exception of China.
Not all the oligarchs whose offspring rub shoulders with wealthy young Britons at our top public schools acquired their cash legitimately.
Only last year, Millfield School in Somerset, which charges around £35,000 ($68,428) annually, was revealed to have accepted a payment in 2011 of fees for one of its Russian pupils from the Latvian bank of a suspect company caught up in a major money-laundering scandal (something the school's bursar could not have known about). The transaction was eventually reported to the National Crime Agency.
But it is high-end real estate, usually in London or the Home Counties, which provides the ultimate safe haven. This is thanks in no small part to the fact that UK law allows so-called 'shell' companies based in secretive tax jurisdictions — whose real owners are often impossible to establish — to hold property.
As a result, some 86,000 British homes are now owned offshore, around half of which are in London, covering upwards of 2.25 square miles of the city and including one in ten of the houses in Westminster. Though of course not every such property is used to hide the proceeds of crime or corruption, plenty are.
Indeed, the anti-corruption organisation Transparency International has used information obtained via the "Panama Papers" — leaked documents detailing the ownership of thousands of offshore firms — to compile a database of 160 London properties purchased using what it describes as "suspicious wealth".
They have an overall value of £4.4 billion ($8.6B), and roughly a quarter were acquired by wealthy Russians. "It's very hard for corrupt people to steal money if they don't have a place to hide it," says a spokesman. "Unfortunately, the UK is one such place."
With this in mind, the Government this week announced plans to force foreign companies to reveal the identities of owners.
There are also moves to introduce a so-called "Magnitsky amendment" — named after a Russian anti-corruption lawyer beaten to death in a Moscow prison — to help freeze the assets of human rights abusers. And there are calls for the Land Registry to insist that all records state the ultimate beneficial owners of UK properties.
New laws also give UK courts powers to impose "Unexplained Wealth Orders" on the owners of assets, forcing them to reveal how they acquired the cash to purchase them.
The procedure is civil, rather than criminal. It requires the target of an order to provide information about the ownership of a particular asset and the means by which it was obtained.
If they fail to comply, the asset can be taken from them, even if authorities are unable to prove beyond reasonable doubt that they acquired it lawfully. Not long ago, the Government filed its first "Unexplained Wealth Order" against the anonymous foreign owner of two London properties worth a reported £22 million ($43M).
It remains to be seen whether the legislation can be applied effectively — or whether expensive lawyers invariably employed by oligarchs and their wealthy chums will be able to frustrate it.
Yet for years, particularly when it comes to Russian loot, the British government has been asleep at the wheel.
Take, for example, the decision by New Labour — whose former Cabinet minister Peter Mandelson had close ties to many wealthy oligarchs, and who now earns a handsome living lobbying for major Russian firms — to introduce a system to allow wealthy foreigners to move to the UK using something called a "Tier One Investor Visa".
Under the 2008 scheme (a prior version of which was created by the Major government, and had run since the mid-Nineties) anyone investing £2 million ($3.9M) in UK business could get temporary residency here. After five years, that residency became permanent. Invest £10 million ($19.5M) and your permanent residency could be fast-tracked and acquired in as little as two years.
During the ensuing seven years, around 3,000 rich foreigners used the system to come to the UK, bringing upwards of £3 billion ($5.8B) to these shores.
Around a quarter were Russian. But there was a catch: no one was properly monitoring where they had made their cash.
The Home Office assumed that British banks would carry out compliance checks. The banks, meanwhile, assumed that if someone has been approved for a Tier One visa, they had a clean bill of financial health.
In 2015, the Cameron government finally twigged that the scheme provided a licence for crooks to launder money through the UK, and introduced proper checks on applicants. Coincidentally, demand for the visas immediately fell off a cliff.
UK banks were also caught napping during last year's "Russian Laundromat" scandal, when it emerged that a network of 21 'ghost' companies set up in the UK had been used to launder between £16 billion ($31.2B) and £65 billion ($127B) from Moscow between 2010 and 2014.
Seventeen British banks — including Lloyds, HSBC, Barclays, TSB, RBS and the Queen's bank, Coutts — blithely handled £600 million of such loot, before the scheme was exposed.
At times, the failure of banks and regulators to catch onto the Laundromat beggared belief. For example, one 'shell' firm caught up in the affair, called Seabon Limited, filed Companies House returns suggesting its turnover was around £10 a year. In fact, bank records showed £9 billion ($17.5B) went through its accounts.
Inevitably, such cash washed up in the property market, pushing up prices in Central London and helping create a ripple effect via which ordinary workers across the country have been priced out of home ownership.
This ongoing market bubble, of course, made already rich investors even wealthier.
Oliver Bullough, an anti- corruption campaigner and author of a number of books about Putin's Russia, remarked this week that the very first London property purchase by a Russian, after the end of the Cold War, was a Knightsbridge flat which went for around £200,000 ($391,018).
"At the time, everyone was laughing about how stupid the buyer was, and how much they had overpaid," he says.
"The same property is now worth £3 million-£4 million, so who's laughing now?"
Just how easily dodgy funds can still be used to buy UK property was sensationally exposed by Roman Borisovich — organiser of the London "Kleptocracy Tour" — a couple of years ago, when he produced an undercover documentary for Channel 4 called From Russia With Cash.
The programme saw him pose as a middle-aged Russian who wanted to buy a high-end London bolthole with his mistress.
During viewings of five homes priced from £3 million-£15 million ($5.8M - $29.3M), Borisovich explicitly told five different estate agents that he was a Russian politician who had acquired the cash for the transaction via corruption, and needed to ensure that the property was purchased anonymously.
Rather than report him to the police, all five of the agents seemed happy to pursue the sale. Perhaps blinded by the six-figure commissions they might receive, several referred him to lawyers known to help Russian buyers set up anonymous companies to own their London homes.
All of which brings us back to Borisovich's tour of properties associated with the Russian regime, where stops have in the past included such architectural delights as Witanhurst in Highgate, which is London's biggest private property aside from Buckingham Palace, boasting 25 bedrooms, a 70ft ballroom, and two mega-basements (it's owned by the family of Putin associate and fertiliser baron Andrey Guryev); and a series of vast homes owned by the family of Vladimir Yakunin, who became very wealthy indeed while running Russia's state railways.
On Thursday, the "Kleptocracy Tour" party was taken to Kensington Palace Gardens, the gated "Billionaires' Row" of detached mansions which is home to Chelsea FC owner Roman Abramovich — who between 2001 and 2008 helped Putin by serving as governor of the remote region of Kamchatka — and several other oligarchs. On arrival, however, camera crews were barred from entering the road by gun-toting policemen manning the gates — Kensington Palace is also on the road.
The remainder of Borisovich's party were tailed, as they walked along the road, by a number of uniformed officers anxious to protect the exclusive properties from being photographed.
Proof that, for all the tough talk of a new Cold War on our doorstep, wealthy Russians in the UK can still enjoy the very best protection that taxpayers' money can buy.