Accidente Sin Huella aka This Man Must Die (All Region DVD) 1969 Michel Duchaussoy, Caroline Cellier, Jean Yanne

A man asserts himself within the life of an actress he believes is somehow responsible for his son's death.
Director: Claude Chabrol
NO NOVEL HERO: This film is based on a British novel of the 1930s written by the poet C. Day Lewis, under the pseudonym Nicholas Blake and is one of several novels by him to feature as its hero the brilliant amateur sleuth Nigel Strangeways. This adaptation, entirely leaves out this leading character and moves the action to France.