The former head of the International Monetary Fund, once talked of as a potential candidate for the French presidency, went on trial in the northern city of Lille to face charges of aggravated pimping and involvement in a prostitution ring operating out of luxury hotels. Strauss-Kahn arrived in a black car with tinted windows and drove into an underground car park, while other defendants entered the courthouse through a crowd of reporters and cameras, accompanied by their lawyers and watched over by a heavy police and military presence. The French economist, known widely as DSK, faces up to ten years in prison and a €1.5 million (£1.13m) fine, as he and more than a dozen other French and Belgian businessmen and police officers go on trial. The trial is scheduled to last three weeks, with Strauss-Kahn not expected to testify before 10 February. Investigators have compiled hundreds of pages of testimony from prostitutes describing the orgies allegedly organised by the 65-year-old Strauss-Kahn and his co-defendants, centred on the Carlton Hotel in Lille, near the Belgian border. Strauss-Kahn says he took part in “libertine” activities but insists he never knew the women involved were prostitutes. It is not illegal to pay for sex in France, but it is against the law to solicit or to run a prostitution business. Hundreds of reporters are covering the trial, making it one of the highest-profile cases in France in years. In 2011, Strauss-Kahn was accused of sexually assaulting Guinean-born maid Nafissatou Diallo in New York, accusations that ended his high-flying finance career. As head of the Washington-based IMF between 2007 and 2011, Strauss-Kahn was also tipped to become the French Socialist party’s presidential candidate for the 2012 election. That was before he was arrested and jailed in New York for four days. Diallo told police he forced her to perform oral sex, tried to rape her and tore a ligament in her shoulder after she arrived to clean his luxury suite at the Hotel Sofitel. Strauss-Kahn was forced to resign from his $500,000-a-year IMF position, even though New York prosecutors dropped the case three months later because they said Diallo had undercut her credibility by lying about her background and changing her account of her actions right after the alleged attack. Strauss-Kahn said the sexual encounter was consensual but called it “a moral failing”. Diallo later reached a confidential settlement with Strauss-Kahn in a civil complaint. No sooner had the US action ended than Strauss-Kahn was named in the “Carlton Affair” case. French police questioned him for 30 hours in 2012 as part of their investigation into the alleged prostitution ring. Prostitutes said that between 2009 and 2011 – precisely when the world’s leaders were looking to the IMF chief for a way out of the global financial crisis – Strauss-Kahn was organising orgies at luxury hotels in Paris, at a restaurant in the French capital and also in Washington. Prosecutors filed preliminary charges of aggravated pimping in March 2012. Months later, Strauss-Kahn’s more than 20-year marriage to prominent French TV journalist and heiress Anne Sinclair crumbled. Investigating judges ordered him to stand trial in 2013, ignoring prosecutors’ recommendation that the charge be dropped.