Investigating judges in the northern French city of Lille have asked for prosecutors' permission to broaden a suspected prostitution probe to examine claims of rape in Washington in December 2010, said an official at the Lille prosecutor's office.
The prosecutor's office will decide next week whether to expand the investigation, the official said. The official was not authorized to be publicly named because of prosecutor's office policy.
Strauss-Kahn is already a target in the Lille prostitution probe, which has mushroomed over the past year into a nationwide scandal. He is facing preliminary charges of alleged aggravated pimping, based on accusations by other people questioned in the investigation.
He denies those charges. He has acknowledged being involved in "libertine" activity while saying that he was unaware of anyone being paid for sex.
The Lille prosecutor's office gave no details of the U.S. rape accusations.
French daily Liberation reported Friday that two Belgian prostitutes questioned in the Lille probe described Strauss-Kahn as using violence during sex at the W Hotel in Washington and forcing one of them to have anal sex despite her protests.
Citing leaked transcripts of witness testimony to Belgian police, also involved in the probe, Liberation cited one of the prostitutes as saying that Strauss-Kahn "used force, he held down my hands, he pulled my hair, he hurt me." The woman is quoted as testifying that another man held her hands down while Strauss-Kahn assaulted her.
In response to a request from The Associated Press, Washington police checked their records for Dec. 16, 2010 and the W hotel - the date and place cited in media reports - and found no reports describing allegations of such activity at the hotel.
Washington police spokeswoman Gwendolyn Crump said French authorities have not reached out to the D.C. police department about the allegations. "We have to have a report of a crime to investigate it," she said.
The hotel's public relations firm issued a statement saying it couldn't comment or confirm which guests were at the hotel the night in question. Bill Miller, a spokesman for the U.S. attorney's office in Washington, declined Friday to comment on the allegations.
The women haven't filed legal complaints in France, but French rules can allow for an investigation even without a formal complaint.
"Strauss-Kahn absolutely contests having committed the slightest violence of any nature, and notes that the declarations made by the young women are contradictory," his French lawyers Frederique Beaulieu and Richard Malka said in a statement.
They noted that the accusations surfaced two days before France's presidential elections. Strauss-Kahn has reportedly said the sex-related accusations against him were part of an effort to discredit him and keep him out of France's presidential race, where he once was considered a leading challenger to President Nicolas Sarkozy.
The Lille probe focuses on a suspected prostitution ring involving prominent city figures and police. Prostitutes questioned in the case said they had sex with Strauss-Kahn during 2010 and 2011 at a luxury hotel in Paris, a restaurant in the French capital and also in Washington, D.C., where he lived while working for the Washington-based IMF, judicial officials say.
Strauss-Kahn is also facing a trial in New York over a lawsuit by a hotel maid who accused him of sexual assault in May 2011. A judge ruled this week that the trial can go forward despite Strauss-Kahn's claim that he had diplomatic immunity.
A French writer had accused Strauss-Kahn of sexually assaulting her during an interview in 2003, but prosecutors ruled last year that too much time had passed to pursue her complaint.
All the accusations against Strauss-Kahn, known as DSK in France, prompted discussion in France about ingrained sexism and sexual harassment in politics and business in this country.
On Friday, France's Constitutional Court drew protests for deciding to change the sexual harassment law to make it harder to prove wrongdoing. In response to the outcry from feminist and other groups, both candidates for France's elections Sunday, President Nicolas Sarkozy and Socialist Francois Hollande, promised to toughen harassment laws if he becomes president.