Death Line (1972) (released as Raw Meat in the US) - pretty terrible UK horror about cannibals living in the tube tunnels near Russell Square who can only communicate by saying "mind the gap". I think Creep may have be a re-make or at least inspired by it. Only made watchable by a fantastic over the top performance by Donald Pleasance as a police chief & a cameo from Christopher Lee.
The long tracking shot showing the bodies in various stages of decay around the cannibals lair with a slow drip, drip, drip noise in the background was quite creepy though.