Ex-IMF chief Dominique Strauss-Kahn arrived in court today 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."