LILLE, FRANCE - Ex-IMF chief Dominique Strauss-Kahn arrived in court Monday to stand trial for “pimping” as part of a prostitution ring, four years after a sex scandal cost him his job and a shot at the French presidency. The disgraced 65-year-old economist finds himself back in the dock - this time in the northern French city of Lille - accused of being at the centre of a vice ring which hired prostitutes for sex parties in Brussels, Paris and Washington.

The silver-haired Strauss-Kahn, dressed in a dark suit, slipped past a throng of journalists to arrive in the empty wood-panelled courtroom, where he paced up and down with his hands in his pockets in front of the imposing stone bench. Strauss-Kahn - once one of the most powerful men in the world - will take the stand alongside a colourful cast of characters including luxury hotel managers, police, freemasons and a brothel owner nicknamed “Dodo the Pimp.”

Nearly 300 journalists are accredited to cover the three-week trial, the first day of which will be dominated by a host of procedural applications.

Lurid details of group sex and high-end prostitution are likely to emerge in the trial for “aggravated pimping in an organised group”, a charge punishable by up to 10 years in prison and a fine of up to 1.5 million euros ($1.7 million).

The trial will be the latest in a series of legal woes offering a peek behind the bedroom door of a man once tipped as a potential challenger to former French president Nicolas Sarkozy.

The ex-head of the International Monetary Fund, known in France as DSK, saw his career implode in 2011 when he was paraded handcuffed in front of the world’s cameras after a New York hotel maid accused him of sexual assault.

Those criminal charges were dropped and the case settled in a civil suit, but six months later Strauss-Kahn’s name cropped up in an investigation into a prostitution ring in northern France and Belgium.

Investigators probing the “Carlton Affair” - named after one of the swish hotels in Lille where local businessmen and police officials organised sex parties - found some of the prostitutes involved had been hired to participate in soirees attended by Strauss-Kahn.

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 lavishing their attention on him 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.

Their probe found that DSK was the “king of the party,” and they are seeking to prove his mere presence gave rise to prostitution as his entourage organised the evenings according to his schedule.

Those attending the gatherings described “carnage with a heap of mattresses on the floor”, with DSK the focus of several women at a time in an atmosphere more of “pure sexual consummation” than a typical swinger’s party.

The trial will kick off with procedural applications, including a request from one of the prostitutes testifying for the trial to take place behind closed doors.

The court will also mull a request to have the trial declared invalid, over allegations investigations were secretly being carried out for eight months before the opening of an official enquiry - fuelling arguments by DSK supporters that he is the victim of a political conspiracy.

The first to take the stand on Tuesday will be the Carlton’s former public relations manager Rene Kojfer who is accused of organising prostitutes for “well-connected men”, often setting them up in his hotel.

He is also accused of doing publicity for another accused, a convicted pimp who owns a string of brothels near the French border in Belgium, where rules are more lax.

Dominique Alderweireld, nicknamed “Dodo la Saumure” - which loosely translates as Dodo the Mackerel, the French slang for pimp - is accused of procuring prostitutes for Kojfer, some of whom were allegedly employed at the orgies attended by DSK.