The 65-year-old economist, whose high-flying career imploded when he was accused of sexually assaulting a New York hotel maid in 2011, is back in court over his role at the centre of a prostitution ring.
Once one of the most powerful men in the world, Strauss-Kahn sat in the dock alongside a colourful cast of characters including luxury hotel managers, a prostitute, police, and a brothel owner nicknamed "Dodo the Pimp."
The silver-haired former finance minister briefly addressed the court in response to a question from one of the presiding judges -- there is no jury in the lower criminal court -- to deny knowing the two main protagonists accused of supplying him with prostitutes through an intermediary.
Arms folded and dressed in a black suit he appeared tense throughout the first day of the three-week trial in the northern French city of Lille, which was dominated by procedural issues.
Lawyers for several of the 14 accused, including Strauss-Kahn, called for the case to be declared invalid over claims some of their clients had their calls intercepted on orders from former prime minister Francois Fillon's office in June 2010 -- eight months before the official investigation began.
The allegation, based on a book written by a former policeman, a witness statement in a separate case and a report by an investigative journalist, meant the accused "could not receive a fair trial," said one of their lawyers, Sorin Margulis.
The lawyers demanded more information on the secret probe and also slammed the three investigating judges for bias, over reports they had stuck a caricature of the Strauss-Kahn up in their office.
Presiding judge Bernard Lemaire, who earlier dismissed a request for ex-prostitutes to testify behind closed doors, said the question about the secret probe would be included in the trial.
Aiding and abetting prostitution
He earlier read out the charges against Strauss-Kahn, accused of being at the centre of a vice ring which hired prostitutes for sex parties in Brussels, Paris and Washington.
"You are accused of aiding and abetting the prostitution of seven persons between March 29, 2008 and October 4, 2011, and of hiring and encouraging the prostitution of these same persons," Lemaire said.
Lurid details of group sex and high-end prostitution are likely to emerge in the trial, in which Strauss-Kahn faces up to 10 years in prison and a fine of up to €1.5 million ($1.7 million) if convicted.
However Lemaire said that "the court is not the guardian of morals but of the law and its proper application."
The 'Carlton Affair'
Then, his name popped up in a probe into the former public relations manager for the Carlton hotel in Lille, Rene Kojfer, and a notorious Belgian brothel-owner Dominique Alderweireld, known as "Dodo the Pimp."
The two are accused of procuring prostitutes for sex parties for local businessmen and police officials in the so-called "Carlton Affair".
The pair had also allegedly procured prostitutes for a member of DSK's entourage -- fellow accused ex-police commissioner Jean-Christophe Lagarde who knew Kojfer through the local freemason brotherhood and who threw the sex parties for the then-IMF chief.
Strauss-Kahn on Monday repeated his claim he had never set foot in the Carlton.
"I saw them for the first time today," he said of Kojfer and "Dodo".
Prostitution is legal in France but procuring -- the legal term for pimping which includes encouraging, benefiting from or organising prostitution -- is punishable by a hefty jail term.
The crux of the case against DSK is whether he knew the women were prostitutes and whether he played a role in organising their presence.
DSK admits to being a "libertine" who enjoys orgies but has steadfastly denied knowing the women were paid.
"In these circumstances one isn't always clothed, and I challenge you to tell the difference between a prostitute naked and any other woman naked," DSK's star lawyer Henri Leclerc, 84, said in 2011.