PARIS â€"  French prosecutor has opened a preliminary investigation into allegations of rape in a Washington hotel by former IMF chief and one-time French presidential hopeful Dominique Strauss-Kahn.

The prosecutor in Lille in northern France followed a request by investigating judges earlier this month to broaden a suspected prostitution probe to examine the claims of rape in December 2010.

The Lille prosecutor's office said in a statement Monday that they are looking into the allegation that Strauss-Kahn may have been involved in a rape during a sex party in the hotel while he was chief of the International Monetary Fund.