Polar(1984)

This film noir tends to stay within very conventional plot lines, as the narration by the main protagonist, private detective Eugene Tarpon Jean-François Balmer, recites a dreary litany of how he wanted to chuck his profession until an attractive woman shows up asking him to investigate the murder of her roommate, a porno star. Soon Tarpon is up to his neck in trouble: the police, gangsters, and the victim's lover are all out to get him.