The affair which ended the political career of John Edwards may eventually land him in the dock, after federal investigators began examining allegations he used campaign funds to pay "hush money" to a mistress.
A contender for the Democratic presidential nomination eventually won by Barack Obama, Mr Edwards admitted at the weekend that his political action committee is under scrutiny for transferring more than $100,000 (£67,000) to Rielle Hunter, shortly before their relationship was exposed. In a carefully-worded statement, Mr Edwards insisted that no money was used improperly by his campaign. "However, I know that it is the role of government to ensure that this is true," he said. "We have made available to the United States both the people and the information necessary to help them get the issue resolved efficiently and in a timely matter."
The investigation will focus on money paid to Ms Hunter's production company by his committee, ostensibly for producing a film about global poverty, which followed Mr Edwards on a campaign visit to Uganda in 2006. Ms Hunter's firm received $100,000 during a four-month span in 2006, and another $14,000 on 1 April 2007.
Investigators will examine whether any of the payments were either related to the couple's affair or intended to prevent Ms Hunter going public with details of their fling. Using money donated to a political action committee for personal use is a federal crime.
Mr Edwards, who had been John Kerry's running mate in 2004, finally acknowledged a long-running affair with Ms Hunter in August last year after months of vigorously denying tabloid reports about the scandal. She gave birth to a daughter in February 2008, but Mr Edwards continues to deny reports that he is the father and a former campaign aide, Andrew Young, has claimed paternity.
Meanwhile Mr Edwards's wife Elizabeth, who is terminally ill with cancer, is about to release a memoir. In it, she reveals that learning of the affair made her vomit, and also describes Ms Hunter as "pathetic".