Former IMF chief Dominique Strauss-Kahn tried to shake off yet another sex scandal Sunday, demanding to be interviewed by judges to clear his name over reports linking him to a vice ring. Until May this year the 62-year-old Socialist was considered favourite to defeat President Nicolas Sarkozy in next year\'s election, but his career has been destroyed by two unproven attempted rape allegations. Strauss-Kahn firmly denied those claims, and prosecutors have dropped both cases, but on Sunday his name was linked to another scandal, an investigation into an alleged call girl network in the northern city of Lille. Reacting after reports he might face questioning, Strauss-Kahn told AFP he wanted to he heard by judges \"as quickly as possible\" to \"end insinuations and extrapolations that are dangerous and once again malicious\". A source close to the investigation confirmed that magistrates might seek to interview Strauss-Kahn \"and a heap of other people\" but not \"in the near future\" as he was thought to have played a \"largely secondary\" role. \"This is not at the heart of the case,\" he said, speaking on condition of anonymity as is normal in France, adding that the main suspects had already been arrested, questioned and in some cases charged. Investigators in Lille believe they have uncovered a well-connected ring that brought women over the frontier from Belgium to have sex with wealthy clients in hotels in the border city, including the four-star Carlton. Five men -- including the director and the public relations chief of the Carlton -- have been arrested in France and charged with pimping, while Belgian police are also investigating on their side of the frontier. Three Lille hotels have been shut down by authorities for three months each while the case is investigated. The case has caused a scandal in Lille, where respected local figures and even senior police officers are reportedly involved, but Sunday\'s reports were the first sign that figures outside the city may be implicated. The weekly Journal du Dimanche cited sources close to the investigation saying Strauss-Kahn, now living in Paris, could be questioned. According to the report, investigators suspect the ring may have dispatched call girls to the United States to entertain him and that he might have taken part in sex parties organised in Paris by one of the Lille suspects. The new scandal erupted just as Strauss-Kahn won some breathing space in his legal battles, when French state prosecutors investigating 32-year-old writer Tristane Banon\'s claims against him decided not to charge him. The Paris prosecutor\'s office decided that, while Strauss-Kahn admitted to grabbing and kissing his accuser, \"which could be regarded as sexual assault\", they did not have enough evidence to charge him with attempted rape. Under French law, sexual assault is a lesser crime than attempted rape and cannot be prosecuted more than three years after the event. Banon\'s complaint dates to 2003, when she claims he tried to rape her in a bare Paris flat. Strauss-Kahn admitted to police he had grabbed Banon but she had refused him and so he had \"released his grip\" and allowed her to go. Banon\'s lawyer David Koubbi said Sunday he had advised his client to drop her case against Strauss-Kahn following this week\'s ruling. But the former finance minister still faces a civil case in New York lodged by 32-year-old Nafissatou Diallo, a hotel chamber maid who alleges he sexually assaulted and tried to rape her on May 14 this year. The French politician was charged, but New York prosecutors later dropped the case after doubts emerged over the maid\'s testimony. Strauss-Kahn has admitted having a sexual encounter with the maid, but denies violence. Strauss-Kahn\'s spectacular fall from grace has threatened to overshadow his party\'s attempt to find another champion to take on Sarkozy in the two-round presidential election April and May next year. Sunday saw the final round of voting in the Socialist Party primary, and Strauss-Kahn turned up discreetly in his former constituency, the Paris suburb of Sarcelles, to vote for one of the remaining candidates. He made no comment to reporters outside.