French investigators questioned a leading presidential hopeful about a writer's claim that former International Monetary Fund chief Dominique Strauss-Kahn tried to rape her.
As the French probe gathers momentum, it has unearthed unexpected claims about Strauss-Kahn.
The writer's mother said in a newspaper interview published yesterday that she herself once had a consensual sexual encounter with him.
Strauss-Kahn is also facing sexual assault charges in New York, where a hotel maid accused him of trying to rape her. Lawyers for the two women met jointly Tuesday with prosecutors in New York. Strauss-Kahn has denied wrongdoing in both cases.
New York prosecutors have asked whether the French writer, Tristane Banon, would be willing to speak to them, but no definite plans have been made, according to a person familiar with the case.
The Manhattan District Attorney's office declined to comment. Ms Banon's lawyer, David Koubbi, did not respond to phone messages seeking comment.
In Paris yesterday, attention turned to Francois Hollande, former head of France's Socialist Party and a poll favourite for next year's presidential race - in which Strauss-Kahn had been an expected contender before his May arrest.
Investigators are interviewing anyone who was told about the 2003 incident in which Ms Banon says Strauss-Kahn tried to tear off her clothes and put his fingers in her mouth and underwear as she fought him off.
She said the alleged attack happened in an empty apartment during an interview for a book she was writing.
Ms Banon's lawyer says Mr Hollande was one of those informed.
Mr Hollande turned up in Paris for questioning yesterday at the special police brigade probing the claim and left about an hour later - as opposed to the six hours Ms Banon's mother spent with investigators and more than five for Ms Banon herself.
"I am completely ready" to be questioned about the "supposed incident", Mr Hollande said in remarks broadcast on French television earlier in the day.
But he insisted before entering the investigators' office and upon leaving it that "this affair doesn't concern me".
Mr Hollande has warned against any "political manipulation" in the case, clearly fearing it could taint his presidential candidacy.
Ms Banon filed her complaint in France after Strauss-Kahn was arrested in the New York case.
The accusations have cast a pall over the Socialists' presidential campaign, as France's leading opposition party struggles to overcome years of divisions to challenge conservative president Nicolas Sarkozy next year.
Questions about Hollande's knowledge of the incident have further clouded the Socialists. Mr Hollande lashed out at those who he said were using the investigation "for political ends".
Meanwhile, the left-leaning daily Liberation ran an interview yesterday with Ms Banon's mother, Anne Mansouret, in which she was asked about leaked reports that she told investigators she once had rough sex with Strauss-Kahn.
"What I can tell you is that it happened in his office at the OECD," she is quoted as saying, without providing further details.
Strauss-Kahn was an adviser in the Paris-based Organisation for Economic Co-operation and Development a decade ago.
Ms Mansouret is a regional Socialist official who was friends with Strauss-Kahn's second wife, Brigitte Guillemette. Ms Mansouret has said that she urged her daughter not to report the 2003 incident at the time.