The £5.25m repossession: One-bedroom flat at billionaire towers near Harrods up for sale Property on the 4th floor of luxury Knightsbridge block One Hyde Park It is being offered for sale by receivers Strutt & Parker The block was developed by property tycoons Christian and Nick Candy Flats have fetched between £5,000 and £7,500 per square foot It is the most expensive block of flats in Britain, with local shops including Harrods and Harvey Nichols. But One Hyde Park in Knightsbridge has had its first repossession - a one-bedroom flat worth £5.25million. The high-end property agency Strutt & Parker said it had been appointed by receivers to arrange a quick sale of the repossessed "entry-level" flat. For Sale: An 'entry level' £5.25 million, one bedroom flat is back on the market at Knightsbridge's One Hyde Park after the block suffered its first repossession Luxury: An apartment in One Hyde Park. Residents have private spas and panic rooms Peter Wetherell, a leading figure in the London property market, said luxury repossessions were uncommon, but could occur if owners" business plans went wrong. "Most of the properties at the top end of the market are cash deals, but for their own personal financing reasons [owners] will gear it up [take out a mortgage on it]," he said. He suggested the repossessed flat might have been bought to sell on. Residents at One Hyde Park are believed to include Ukraine's richest man, Rinat Akhmetov, the Kazakh singer Anar Aitzhanova and the model Naomi Campbell's boyfriend Vladislav Doronin. They enjoy "bespoke services and amenities" including a private spa, squash court, cinema, 21-metre swimming pool, gym, a golf simulator and a wine cellar. Property tycoons: The block was developed by Nick Candy, pictured with wife Holly Valance, left, and his brother Christian Candy, pictured with his wife Emily, right Million pound view: The flats at One Hyde Park that are sold for up to £5,000 per sq ft boast stunning views The block has high-security features including iris recognition in the lifts, panic rooms and bomb-proof windows, and all post is X-rayed. In addition to a concierge and valet, residents also enjoy room service via a tunnel from the five-star Mandarin Oriental hotel next door. Rinat Akhmetov, Ukraine's richest man - estimated worth £143.8m Folorunsho Alakija, Nigerian oil tycoon - estimated worth £81.9m Sheikh Hamad bin Jasmin bin Jabr Al Thani - estimated worth £40.4m Irina and Viktor Kharitonin, Russian pharmaceuticals, - estimated worth £33.1m Professor Wong Wen Young, Taiwanese entrepreneur - estimated worth £29.1m The imposing glass tower was unveiled in 2011 at a lavish party with a guest list that included Bernie Ecclestone, Lord Lloyd-Webber and Gary Lineker. Flats in the block, built by the developers Nick and Christian Candy, fetch nearly double the average for the location, averaging between £5,000 and £7,500 per square foot. Other apartments in the complex have sold for up to £140million. Mr Wetherell said: "One Hyde Park is an example of the building everyone loves to hate, but it redefined the word luxury in central London property and it's been a resounding success story." Critics complain that flats in the block are rarely occupied, and Tracy Kellett of the home finders BDI said: "It has now been categorically proven that One Hyde Park was the worst property investment in London. Many prime London properties have gained 50 per cent since 2007 - One Hyde Park has seen no uplift.