Graphic: the house that Barack bought | The key players | Timeline: Barack and the billionaire

A British-Iraqi billionaire lent millions of dollars to Barack Obama's fundraiser just weeks before an imprudent land deal that has returned to haunt the presidential contender, an investigation by The Times discloses.

The money transfer raises the question of whether funds from Nadhmi Auchi, one of Britain’s wealthiest men, helped Mr Obama buy his mock Georgian mansion in Chicago.

A company related to Mr Auchi, who has a conviction for corruption in France, registered the loan to Mr Obama's bagman Antoin "Tony" Rezko on May 23 2005. Mr Auchi says the loan, through the Panamanian company Fintrade Services SA, was for $3.5 million.

Three weeks later, Mr Obama bought a house on the city's South Side while Mr Rezko's wife bought the garden plot next door from the same seller on the same day, June 15.

Mr Obama says he never used Mrs Rezko's still-empty lot, which could only be accessed through his property. But he admits he paid his gardener to mow the lawn.

Mrs Rezko, whose husband was widely known to be under investigation at the time, went on to sell a 10-foot strip of her property to Mr Obama seven months later so he could enjoy a bigger garden.

Mr Obama now admits his involvement in this land deal was a “boneheaded mistake”.

Mrs Rezko’s purchase and sale of the land to Mr Obama raises many unanswered questions.

It is unclear how Mrs Rezko could have afforded the downpayment of $125,000 and a $500,000 mortgage for the original $625,000 purchase of the garden plot at 5050 South Greenwood Ave.

In a sworn statement a year later, Mrs Rezko said she got by on a salary of $37,000 and had $35,000 assets. Mr Rezko told a court he had "no income, negative cash flow, no liquid assets, no unencumbered assets [and] is significantly in arrears on many of his obligations."

Mrs Rezko, whose husband goes on trial on unrelated corruption charges in Chicago on March 3, refused to answer questions about the case when she spoke by telephone to The Times.

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