Originally rated "R" in the U.S. in 1970, some violence and sex was cut to be re-rated "PG" for a 1972 theatrical re-release. Paramount restored the cut footage (and the "R" rating) in the 1992 video release.
The original UK cinema version was heavily cut by the BBFC to remove shots of rape and nudity, and the 1988 CIC video featured a heavily abridged version of the film.