Patrick Poivre d'Arvor, the popular former presenter of the prime-time news on French channel TF1, was questioned by investigators from the Paris violent crimes squad, said the sources close to the enquiry, who asked not to be named.
The detectives are investigating a claim by the French writer Tristane Banon, 32, that Strauss-Kahn tried to rape her in 2003. On the basis of their findings prosecutors will decide whether to press charges.
Poivre d'Arvor, a journalist and writer, was an acquaintance of Banon and is one of about 10 people whom she and her mother Anne Mansouret say they told about the alleged attempted rape at the time.
Strauss-Kahn has dismissed the alleged attack as "imaginary".
Police have already questioned top French presidential hopeful Francois Hollande and other acquaintances close to Banon and Strauss-Kahn.
When Banon brought her legal action this month, Strauss-Kahn was already facing separate charges in New York, where he is accused of sexually assaulting and trying to rape a hotel maid.
He denies all the charges but the New York case has already derailed his hopes of beating President Nicolas Sarkozy to the presidency next year.
Hollande now polls among those most likely to win.