Film had a re-shot alternative ending which was less horrific and graphic when the film was shown on television in the early 1970s. This alternative ending can be seen in multiple home released versions available on the Internet.
Shots from "Eye of the Cat"'s opening sequence, as well as a few shots from a funeral sequence flashback that occurs later in the film, are seen briefly in a 1973 "Night Gallery" titled, "Die Now, Pay Later" (Season 3, episode 16).
In pre production, this was known as " Wyler " , and it was intended as a starring vehicle for Terence Stamp.