Prosecutors have opened an investigation into former US president Mr Bill Clinton's last-minute pardon of fugitive financier Marc Rich, a source familiar with the case said.
US Attorney Ms Mary Jo White in New York "is trying to determine if there was a transfer of money to buy the pardon", the source told reporters.
In a statement issued through a spokeswoman last night Mr Clinton said: "As I have said repeatedly I made the decision to pardon Marc Rich based on what I thought was the right thing to do.
"Any suggestion that improper factors, including fund-raising for the [Democratic National Committee] or my library, had anything to do with the decision are absolutely false."
"I look forward to co-operating with any appropriate inquiry."
Rich's former wife Denise has been a major contributor to the Democratic Party, the successful Senate campaign of Ms Hillary Rodham Clinton and the Clinton Presidential Library Fund.
Ms White is expected to examine bank and telephone records and other documents to determine whether there was a link between the contributions and Mr Clinton's decision to grant the pardon, the source said.
Ms White, who was appointed to her post by Mr Clinton in 1993, has said the pardon was granted without consultation with her office, which charged Rich in 1983.
A spokesman said Ms White had no comment and a Justice Department spokeswoman in Washington also declined comment. Mrs Clinton, through a spokesman, referred questions to her husband's transition office.
The constitution gives presidents the right to grant pardons. But Rich's pardon, one of 141 granted by Mr Clinton on January 20th - his final day in office - has prompted sharp bi-partisan criticism and hearings by House and Senate committees.
Before his pardon Rich was wanted by the US Justice Department on charges of evading more than $48 million in taxes, fraud and participating in illegal oil deals with Iran.
AP