Some of Elie Nahas' alleged associates are on trial in Marseille, Radio France Internationale reported. He is a fugitive.
Prosecutors say Nahas paid well over a million dollars for Mutassim Gadhafi's birthday party in 2004. Mutassim was killed in Libya last year with his father, dictator Moammar Gadhafi.
Because France was friendly with the Gadhafi regime, Nahas' ties to his son delayed an investigation in 2007 and 2008, Patrick Rizzo, representative of a group advocating against prostitution, said.
Nahas allegedly ran an operation that recruited models, beauty pageant winners and others to an operation that catered to rich Middle Easterners, charging them thousands of dollars. The group was reportedly especially active during the Cannes film festival.
Felix Farias, a Venezuelan and one of the eight people on trial in Marseille, was refused entry to France in 2007 when he arrived at a Paris airport with eight women, all of them headed to Cannes.