French police probing an attempted rape accusation against ex-IMF head Dominique Strauss-Kahn have questioned his daughter Camille, a friend of his alleged victim, a judicial source says.
Police questioned the Socialist politician's daughter and her mother, his ex-wife Brigitte Guillemette, on Friday over claims by French writer Tristane Banon that he tried to rape her in 2003, said the source, who asked not to be named.
Guillemette is Banon's godmother and Camille Strauss-Kahn was a friend of Banon, now 32, at the time of the alleged attack, which Banon says took place as she tried to interview Dominique Strauss-Kahn for a book.
Police also questioned Banon and her mother, Socialist politician Anne Mansouret, last week.
Mansouret has said recently in several press interviews that she had contacted Guillemette shortly after the alleged sexual assault on her daughter.
Strauss-Kahn has dismissed the alleged attack as "imaginary" and his lawyers are counter-suing Banon claiming defamation.
Strauss-Kahn is in New York pending legal proceedings for allegedly sexually assaulting and trying to rape a hotel maid there. Prosecutors have admitted doubts about his accuser in that case, raising the prospect that the charges could be dropped.
French detectives are also expected to question Francois Hollande, a leading candidate for the opposition Socialists' nomination to run for president of France next year.
The New York case has already derailed the electoral hopes of Strauss-Kahn, previously favourite to beat President Nicolas Sarkozy in the 2012 presidential election.
Banon has said Hollande knew of her claims at the time of the alleged attack but he has denied having any detailed knowledge of it.
He told reporters on Tuesday that he wanted to be questioned "as soon as possible" and warned against political "manipulations and manoeuvres" in the case.
Guillemette also said she is suing Mansouret over claims she made in an interview in L'Express magazine relating to her alleged knowledge of another incident involving Strauss-Kahn.