Disgraced former International Monetary Fund boss Dominique Strauss-Kahn told a French court Tuesday that he was unaware that women who participated in orgies at luxury hotels in Paris and Washington D.C. were prostitutes.

65-year-old Strauss-Kahn and 13 co-defendants are on trial in this northern French city, accused of aggravated pimping in connection with a sex ring centered on the Hotel Carlton in Lille.

In his first testimony since the trial began Feb. 2, Strauss-Kahn reaffirmed his long-standing defense that he ignored the "prostitutional character" of the women who took part in his orgies.

Strauss-Kahn's arrival at the courthouse was disrupted by three topless protesters from the provocative group Femen, who were detained by police.

#Carlton> 2 femens tentent de grimper sur le toit de la voiture de #DSK en criant "macs-clients déclarés coupables" pic.twitter.com/dezmRVMefY — itele (@itele) February 10, 2015

Strauss-Kahn's chances of becoming French president were ruined over an unrelated sex scandal in New York.

The economist, known widely as DSK, faces up to 10 years in prison and a 1.5 million-euro ($1.7 million) fine if convicted.

Strauss-Kahn is on trial with 13 other defendants accused of operating a prostitution ring out of luxury hotels in Paris, Washington D.C., Lille and Brussels.

The trial began Feb. 2. The court has so far heard testimony from some of Strauss-Kahn's fellow defendants, who include a Belgian brothel owner, local businessmen, a police officer and hotel staff accused of organizing sex parties for Strauss-Kahn's benefit.

#DSK tells court the soirées only happened around 4 times a year. He was v busy 'saving the world' during financial crisis #CarltonLille — Angelique Chrisafis (@achrisafis) February 10, 2015

Investigators have compiled hundreds of pages of testimony from prostitutes describing the orgies.

It's not illegal to pay for sex in France, but it's against the law to solicit or to run a prostitution business.

Prostitutes questioned in the case said that between 2009 and 2011 — when the IMF chief was dealing with a global financial crisis — Strauss-Kahn was organizing orgies at luxury hotels in Paris, at a restaurant in the French capital and also in Washington.

Hundreds of reporters are covering the trial.