Beware of Blondes(1950)

Original title: Méfiez-vous des blondes

Back from a stay in the Far East, a woman who knew the names of the chiefs of a drug ring is murdered. Georges Masse, the famous reporter, decides to investigate, accompanied by his faithful photographer P'tit Louis. He will come across some unappetizing characters like M. Dubois, a killer, Luigi Costelli, a dangerous trafficker and a beautiful but dubious lady, Suzanne Wilson. After being himself suspected, Masse will make the truth triumph.