The Girl Grabbers(1968)

Nick and Louie are two degenerates who assault a young woman in her Greenwich Village apartment. The woman's boyfriend, Paul, embarks on a quest to find and get revenge against the two thugs which leads him to the seedy underbelly of New York's red light district from a strip club to a local brothel where Paul meets and has sexual encounters with a few women to learn the identity of the two 'girl grabbers' leading to a drug deal between the two thugs and a powerful gangster.