Regarding the name of the cat, Asmodeus. Asmodeus is a demon who specializes in spreading lust. He preys on common people and royalty and even divine beings.
The story was previously filmed by Fritz Lang as Man Hunt (1941). This was a very free adaptation - Geoffrey Household later said that Lang had "made a smashing film", but it hadn't been much like the book. This television version also took several liberties, but was generally closer in plot and it, too, won praise from the author.
Michael Byrne plays a Nazi interrogator in this film and would go on to play a very similar role, that of a vicious Nazi officer, in Indiana Jones and the Last Crusade (1989). Whereas Michael Sheard plays Adolf Hitler in both this and the aforementioned Indiana Jones film. Sheard also portrayed Hitler in Hitler's Last Secret: Seeds of Destruction (1978), The Dirty Dozen: Next Mission (1985) and Hitler of the Andes (2003).