When originally released in the UK, the film was heavily cut to receive a lower certificate from the BBFC. This version excised most of the violent and horrific scenes, most notably from the last third of the film, including both scenes where Brent is forced to attack Nova, the revelation of the underground humans' true appearance, the fight Brent and Taylor are forced to have in the prison cell, the killing of the mutant guard on a spiked door, and much of the shoot-out at the film's climax. This cut version was later shown on British TV, c.1991, even though all UK video and DVD releases have been fully uncut and rated '15' since 1987.
