Rising Damp 1980 Film.

A feature film version was made in 1980, reusing several storylines from the television series. As Richard Beckinsale had died the year before, Christopher Strauli was cast as a new character, art student John. The character of Alan is briefly referenced, as having left. The film's theme song features lyrics by Eric Chappell and was released as a 7" single. The B-side features comedy dialogue between Rigsby and Miss Jones.
Philip is revealed not to be a chief's son from Africa, but from Croydon, adopting his false persona to start a new life and gain respect. When Rigsby finds out, he tells Philip that he believes he must have some royal ancestry and he does not tell the rest of the characters about his deception. This plotline is from the original stageplay The Banana Box.