Dominique Strauss-Kahn leaves court in Lille, France, after questioning by three judges over his role in a prostitution case March 26, 2012. He appeared at the Lille court two days earlier than scheduled. Reuters/Pascal Rossignol

The former chief of the International Monetary Fund, Dominique Strauss-Kahn, was charged by a French court Monday evening over his alleged involvement in a prostitution ring, according to reports.

The BBC reported that Strauss-Kahn, who had to resign in disgrace from his position at the IMF last year in the wake of a sexual assault charge in New York, was questioned by judges and police in the northern French city of Lille.

One of Strauss-Kahn’s attorneys, Richard Malka, said his client denies the charges.

He firmly declares that he is not guilty of these acts and of never having the least inkling that the women he met could have been prostitutes, Malka told reporters.

The New York charges were dropped when the credibility of the accuser, a hotel chambermaid, was questioned.

In the current case, Strauss-Kahn admitted attending parties where women were apparently available for sex, but he denied knowing they were paid prostitutes at the time. In France, the case is being called “The Carlton affair,” in reference to the hotel where orgies were reportedly held, some involving Strauss-Kahn.

The judges in Lille are also investigating associates of Strauss-Kahn who also may have been linked to the prostitution ring.

Strauss-Kahn faces preliminary charges of procuring prostitutes and involvement in an organized gang, one of his lawyers said.

The 62-year-old former IMF head, who could face up to 20 years in prison if tried and convicted, was released on 100,000 euros ($135,000) bail.

Prosecutors say he cannot contact defendants, plaintiffs, witnesses or the media in relation to the case.

The allegations relate to his supposed involvement in a vice ring that hired prostitutes for hotel orgies, mainly in Lille, but also in Paris and Washington, the BBC reports.

Until his downfall last year, DSK was considered a leading contender for the French presidency for the Socialist Party.

Having relations with an escort does not constitute a crime and is a matter of private behaviour, perfectly legal among adults, his lawyer noted.

The Lille case centres on allegations that a prostitution ring organised by Strauss-Kahn's business associates supplied clients at the city's Carlton Hotel.

Already in the case, eight people, including two Lille businessmen and a police commissioner, have been arrested, and construction firm Eiffage fired an executive suspected of using company funds to hire sex workers.

Judges had the option of putting him under investigation for having potentially benefited from misappropriated company funds if he knowingly attended prostitute sessions paid for by his executive friends using expense accounts.

Instead, the investigation will focus on the pandering angle, and whether Strauss-Kahn was aware that the women at the parties were prostitutes supplied by pimps.

In itself, using prostitutes is not illegal in France.

The highly anticipated hearing was originally scheduled for Wednesday but was moved up by two days for unknown reasons.