PARIS - French investigators questioned a leading presidential hopeful Wednesday about a writer's accusation that Dominique Strauss-Kahn tried to rape her.

As the French probe picks up steam, it has unearthed unexpected claims about the former head of the International Monetary Fund. The writer's mother said in a newspaper interview published Wednesday that she herself once had a consensual sexual encounter with Strauss-Kahn.

Strauss-Kahn is also facing sexual assault charges in New York where a hotel maid accused him of trying to rape her. Lawyers for two women met jointly Tuesday with prosecutors in New York. Strauss-Kahn has denied wrongdoing in both cases.

In Paris on Wednesday, 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 writer Tristane Banon says Strauss-Kahn tried to wrench off her clothes and shoved his fingers in her mouth and underwear as she fought him off. She says it happened in an empty apartment during an interview for a book she was writing.

Banon's lawyer says Hollande was one of those informed.

Hollande showed up for questioning Wednesday afternoon at the special police brigade probing the claim and left about an hour later -- compared to the six hours Banon's mother spent with investigators and more than five for Banon herself.

"I am completely ready" to be questioned about the "supposed incident," Hollande said in remarks broadcast on French television earlier in the day.

However, he insisted before entering the investigators' office and upon leaving it that "this affair doesn't concern me."

Hollande has warned against any "political manipulation" in the case, clearly fearing it could taint his presidential candidacy.

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. Hollande lashed out at those who are using the investigation "for political ends."

Meanwhile, the leftist daily Liberation ran an interview Wednesday with 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 Organization for Economic Cooperation and Development a decade ago.

Mansouret, contacted by The Associated Press, would not comment on the report or anything she told investigators.

Mansouret is a regional Socialist official who was friends with Strauss-Kahn's second wife, Brigitte Guillemette. Mansouret has said that she urged her daughter not to report the 2003 incident at the time.

The AP does not name victims of alleged sex crimes unless they agree to be identified or publicly identify themselves, as Banon has.

After Tuesday's meeting between Banon's lawyer and the lawyers for the New York hotel maid, it remained unclear what the prospects were for convergence between the complaints.