One of the original 39 Video Nasties.
Horror author Stephen King claims in his book "Danse Macabre" that this film is "the work of morons with cameras."
The opening of the double murder scene was the last to be filmed. It was shot during the spring of 1968, several months after principal photography ended, as indicated by the green plants in contrast to the winter setting of the bulk of the film.
Reissued theatrically in the early 1980s as 'Blood Orgy' in multi-film packages with similar movies.