This is more properly known as Quatermass and the Pit, and is the third Quatermass movie from Hammer Films (actually adapting a TV serial, which I suppose is kind of like what Hammer did with the first two Doctor Who Dalek serials).
What is your source for this information regarding the two Amicus Dr Who movies? What part did Hammer play in these films?
I think Christopher
just made the mistake of confusing the lesser known Amicus Productions with Hammer Films, which (per wikipedia) are similar in visual style and share stars like Christopher Lee and Peter Cushing. Hammer didn't have anything to do with the two Cushing Doctor Who movies, as far as I know.