Kiss Me Monster (1969)

aka's: Küss Mich, Monster/Besame Monstruo/Castle Of The Doomed

A pair of stripteasing artist roommates, who bunk in a groovy little bungalow practically lost in deep shag carpets, turn freelance detectives when they stumble upon a secret message hidden in the strains of a song. Before you know it they've tracked the source to a Caribbean island where an ancient castle hides a mad scientist experimenting on (usually naked female) captives in his bid to create a strain of supermen.