Former IMF chief Dominique Strauss-Kahn has been handed preliminary charges alleging he was involved in a French prostitution ring, his lawyer said Monday.

Investigating judges questioned Strauss-Kahn for several hours Monday. After he left his lawyer, Richard Malka, told reporters his client had been accused of procuring prostitutes and involvement in an "organized gang."

Strauss-Kahn denied any wrongdoing, Malka said, adding it's wrong to prosecute Strauss-Kahn for "simple libertine activity."

Under French law, preliminary charges mean authorities have reason to believe a crime was committed but allow more time for investigation.

Police are probing a suspected prostitution ring in France and neighbouring Belgium that has implicated police and other officials. They have questioned prostitutes who 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. Strauss-Kahn lived in the U.S. capital while he was head of the IMF before resigning his position in May.

Two men with ties to Strauss-Kahn have been put under preliminary investigation in France on charges including organizing a prostitution ring and misuse of corporate funds.

Strauss-Kahn's name surfaced in the investigation last fall and his lawyer has asked that Strauss-Kahn be allowed to tell his side of the story. One of Strauss-Kahn's lawyers has said that the former French presidential hopeful never knew that the women at orgies he attended were prostitutes.

"He could easily not have known, because as you can imagine, at these kinds of parties you're not always dressed, and I challenge you to distinguish a naked prostitute from any other naked woman," Henri Leclerc told French radio Europe 1 in December.

'The Carlton Affair'

French newspapers have dubbed the investigation "The Carlton Affair" after the name of the expensive Lille hotel where some of the meetings took place. Investigators are seeking to discover whether prostitutes were paid using corporate funds from a large French construction company.

It is Strauss-Kahn's latest run-in with police over alleged sexual misconduct.

Strauss-Kahn was charged by New York police in May with making a hotel maid perform oral sex. The one-time French presidential hopeful has said the sexual encounter was "inappropriate" but not violent.

New York prosecutors dropped the case against him in August because the woman had undercut her credibility by lying about her background and changing her account of her actions right after the alleged attack. She says she was truthful about the encounter and is pursuing her claims in a lawsuit.

In a separate case last October, French prosecutors refused to pursue an allegation by a young French writer of attempted rape by Strauss-Kahn.

Strauss-Kahn quit the International Monetary Fund after a New York hotel maid said he sexually assaulted her in May. The charges were later dropped.