Lille (France), Feb. 10 (Reuters): Dominique Strauss-Kahn told a French court today he did not know the women at "festive and playful" sex parties he attended were prostitutes, saying that would have been too risky given his then-role as head of the IMF.

Strauss-Kahn, 65, is accused of instigating about a dozen parties he knew involved prostitutes from 2008 to 2011 in the northern French city of Lille, Paris, Washington and Brussels.

He acknowledged his fondness for "libertine" parties with a small group of friends who at times invited him to join "a lunch or something more festive and playful" in Paris.

He never organised the parties nor asked others to organise them, and would not have attended had he known the women were prostitutes, Strauss-Kahn said.