Tycoon hit by a £20m repossession

The developer son of Turkish immigrants became a billionaire by riding the property wave – until it crashed

In the boom years of the buy-to-let market, businessman Cevdet Caner made a career, and a sizeable fortune, in the property market. So it is perhaps ironic that following the collapse of his company in the recession his £20m home has been seized in what is thought to be Britain's biggest ever house repossession.

Last week court-appointed bailiffs officially repossessed the six-storey luxury flat in Charles Street in London's exclusive Mayfair district. And today the house will be put on the market by estate agents Hamptons International together with Sotheby's, with a list price of £20m.

The sale brings to an end a rags-to-riches tale which has seen Mr Caner, son of a modest Turkish immigrant, rise to become to a billionaire property magnate with a portfolio of nearly 30,000 properties, and then go bust.

The repossession saga started in December last year, when administrators were appointed to oversee debts of £1.2bn that Mr Caner owed various creditors following the collapse of his property empire in August. Then they put the house up for sale, evicting the businessman in the process.

But Mr Caner, 35, fought the sale and eviction, claiming that he had twice offered to repay the mortgage on the property but had been rejected by Investec, his mortgage lender. Investec refused to comment on this suggestion.

He also blamed his financial woes on the banks who had pledged to loan him money but then apparently reneged on the deal, rather than on any mismanagement on his part.

However he lost his battle. Mr Caner moved out two weeks ago and on Friday the receivers Allsop, working for Investec, confirmed it had taken control of the property, "a rare beast" on "one of the best sites in Mayfair", according to Jon Gershinson, a partner at Allsop.

The value of the property is twice that of Britain's previous biggest repossession: in September, Robert Bonnier, 38, had his £11m home in Holland Park, west London, seized. A spokeswoman for Hamptons said: "It is highly unusual for a property at the top end of the residential market like this to be repossessed."

Mr Caner bought the property in July 2007 for £16m and spent £6m refurbishing it. It boasts 11,500 square feet of floorspace and has a mews house and underground swimming pool. It also has a wood-panelled boardroom, which the Austrian-born Mr Caner used as an office when in London.

Planning permission was obtained in December last year to demolish a carriage building at the rear of the house and rebuild it as a garage, with a four-bedroom apartment upstairs and a sauna, gymnasium and solarium in the basement. It is unclear whether this work was ever carried out.

Mr Caner was born in Austria, the youngest of seven offspring of Turkish immigrants to Europe. He began property investments in 2003 after reading that income from rent would easily cover the cost of borrowing money to buy buildings.

He had started his first venture, a company operating call centres, as a business school student in his hometown of Linz – where he was also president of the Young Socialists. He gradually reduced his stake in that company, CLC, until he was ousted by the board in 2002. Two years later it went bust.

Then between 2004 and 2007, relying on bank borrowing, he spent £1.5bn buying 27,000 Communist-era social housing units in East Germany, while getting used to a lavish lifestyle. As well as his Mayfair home, he owned a £4m house in Berlin, and he once said that he spent 500 hours a year in his private jet commuting between London, Berlin and Linz, where his aides managed 200 companies registered in Germany, Jersey, Liechtenstein and Luxembourg.

The business came unstuck after wrongly predicting that home ownership in Germany was set to rise at the rate it had in the UK.

Zurich-based bank Credit Suisse is now the main creditor heading a list of many, and is owed about £250m.

Mr Caner says his undoing began in March 2007 when Credit Suisse offered him a £93m bridging loan while his German houses were being sold. "It was my biggest mistake," he told Bloomberg news agency. "I was too greedy and wanted to grow my portfolio faster."

Despite his current predicament, Mr Caner plans to fight Credit Suisse's demands with a view to clearing his name and, incredibly, returning to property investment. "German real estate looks extremely interesting," he said. "That's why I have to fight to show that the wrongdoing was all on the other side. I know I'm right."