Haenel, now 30, first detailed her allegations against Ruggia Sunday on the French investigative website Mediapart. She says Ruggia, who directed her first film, "Les Diables", repeatedly touched her inappropriately when she was between 12 and 15 years old.
Ruggia has categorically denied the allegations via his lawyer Jean-Pierre Versini. The Paris prosecutor's office confirmed to The Associated Press that an inquiry opened Wednesday into Ruggia for "sexual aggressions against a 15-year-old minor."
Haenel told French media this week that she did not wish to file a formal complaint because she didn't trust the French justice system.