Strauss-Kahn was tipped to become French president before being accused of sexual assault by a New York hotel chambermaid in 2011. U.S. criminal charges were subsequently dropped, and the allegations that he participated in a French sex ring centered in the northern French city of Lille emerged later.

"Did Dominique Strauss-Kahn pay prostitutes? The answer is no. Did he pimp prostitutes for others? The answer is no," Lille Prosecutor Frederic Fevre told the court before requesting Strauss-Kahn's acquittal.

The prosecution's demand highlighted the difficulty of a potential conviction of Strauss-Kahn, 65. The trial is due to finish this week, with closing statements from the defense on Wednesday, but a verdict is not expected immediately.