Dominique Strauss-Kahn to be questioned over prostitution ring Dominique Strauss-Kahn faces more questioning by French police. Photograph: David Karp/AP Dominique Strauss-Kahn, the former head of the International Monetary Fund, is to be questioned on Tuesday by French police investigating an alleged prostitution ring. Investigators in Lille are probing a suspected prostitution ring in the northern French city, where women from France and massage parlours in Belgium were allegedly supplied for hotel customers and local officials. Those under investigation in what has been dubbed the Hotel Carlton affair, after the expensive Lille hotel where some of the meetings took place, have included a senior police officer, a local barrister and businessmen. Strauss-Kahn, who was forced to quit his position at the IMF and shelve aspirations to become the next French president last year, has been keeping a low profile since his return to France after sexual assault charges against him in New York were dropped. French police have questioned prostitutes who said they had sex with him during 2010 and 2011 at a luxury hotel in Paris, a restaurant in the French capital and also in Washington DC, where Strauss-Kahn lived while he was head of the IMF. Two men with ties to him have also been put under preliminary investigation in France on charges including organising a prostitution ring and misuse of corporate funds. His name surfaced in the investigation last Autumn and his lawyer has asked that Strauss-Kahn be allowed to tell his side of the story. One of his 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 station Europe 1 in December. Strauss-Kahn was charged by New York police in May with making a hotel maid perform oral sex. He has said the sexual encounter was "inappropriate" but not violent. The case collapsed in August because of doubts about the credibility of his accuser, Nafissatou Diallo, although 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 him. The Paris prosecutor's office dropped the investigation into writer Tristane Banon's claim that Strauss-Kahn tried to rape her during a 2003 interview for a book the then-23-year-old was writing, saying they couldn't send him to trial because it happened too long ago.