Une Affaire privée (2002)

Divorced private detective Francois Maneri is assigned by his agency to investigate the disappearance of Rachel, a young student who has been missing for six months. After interviewing Rachel's family, friends and classmates, Francois is attacked and injured by an anonymous assailant and becomes reluctant to continue his search. But when Rachel's body is found, Francois is drawn deeper into the investigation as he discovers the dead girl's secret life.