Ilsa, the Mad Butcher (1977)

Greta - Haus ohne Männer

Greta a vicious warden, runs a mental-hospital for young women. A girl deliberately "checks" in to the hospital to find out what has happened to her sister who stayed there. Meanwhile Greta and one of the guards are forcing the inmates to have sex with male prisoners, filming them and selling the recordings as pornoflicks.