Les 3 font la paire (1957)

A bit-part actor (Jean Rigaux) is murdered in Montmartre during the filming of a comedy directed by the eccentric filmmaker Henri Valpreux (Darry Cowl). Commissioner Bernard (Michel Simon), encouraged by his wife (Pauline Carton), who is proud to see him take on a “Maigret”-style role, leads the investigation. His inquiries run into the conflicting accounts of the three eyewitnesses: director Valpreux (Darry Cowl), producer Duval (Gilbert Boka), and stagehand Dumont (Émile Genevois). The discovery of a strip of film that captured the crime seems to provide the answer—until two suspects emerge: clowns from the Médrano Circus (Philippe Nicaud), twin brothers who each confess to the murder to protect the other. A prostitute (Sophie Desmarets), who spent the night with the killer, is asked to identify him. But the real culprit, a petty crook (also played by Philippe Nicaud) who looks just like the twins, remains untraceable. The underworld, fearing a media scandal, will eventually eliminate him.