The Outside Man

The Outside Man (French: Un homme est mort) is a 1972 French-Italian thriller set in Los Angeles, directed by Jacques Deray and starring Jean-Louis Trintignant, Ann-Margret, Roy Scheider, and Angie Dickinson.

Flying to Los Angeles, he checks into a hotel and drives out to the victim's luxurious home.

Back at the hotel, he discovers that his room has been stripped, including his passport and plane ticket.

He calls up his boss in Paris, Antoine, who tells him to find an old friend, Nancy, who works in a topless bar.

The answer is clear: it was Kovacs son, who has inherited his father's profitable empire and his trophy wife.