Down Town (1975)

Can Al Pereira (Jess Franco) ever catch a break? Stuck in Puerto Rico, down on his luck and broke, he finally gets a job seeing if Carlos Ramos (Eric Fauk) is cheating on his wife Cynthia (Lina Romay), who soon falls into bed with our detective hero and pins the murder of her husband on him, as he was the last person to see Carlos alive. Yet when he explains this to the police, they offer to bring him to meet with the dead man's wife to confirm the story. That's when the truth comes out.