The Whole Truth (1958)

On the French Riviera, movie producer Max Poulton is on location shooting a film starring his lover, Gina Bertini. But when the rueful Max ends his fling with Gina to return to his loyal wife, Carol, the jilted actress threatens to reveal details of their affair to Carol. Later, at a party at Max's villa, investigator Carliss arrives with news that Gina has been killed and that Max is a murderer suspect.