Tell Me Whom to Kill (1965)

On the Côte d'Azur, a beautiful adventuress and a strange German tourist set themselves the courteous challenge of discovering a war treasure lying at the bottom of a bay. But Basta, an old original who alone knew the location of the wreck, is murdered. And Pitou, the jovial nightclub owner, is determined to get his hands on all the loot.

Unfortunately the movie Tell Me Whom to Kill is not yet available on HBO Max.