Prosecutors in Lille said Monday that Strauss-Kahn may have been involved in a gang rape during a sex party in December 2010 in a Washington, DC hotel. Authorities say three other people were allegedly involved in the incident.
A prostitute testified that Strauss-Kahn and friends forced her to have sex in a group. She has not filed a formal complaint.
He is also facing charges in Lille in connection with a prostitution case.
Strauss-Kahn has denied the allegations against him and said he is not guilty of any violence.
Earlier this month, he counter-sued the maid, Guinea native Nafissatou Diallo, saying she cost him not only his IMF job but also political opportunities including the French presidency.
Diallo's lawyers called the $1 million lawsuit a publicity stunt.
Socialists had earlier touted Strauss-Kahn as a likely president candidate. Instead the party backed newly elected President Francois Hollande, who defeated former leader Nicolas Sarkozy in a runoff vote earlier this month. VoA.