Martinus was best known for his directing work on Doctor Who - helming 26 episodes of the BBC sci-fi drama in all.
His efforts included William Hartnell's final story 'The Tenth Planet' (1966) and Jon Pertwee's first outing 'Spearhead From Space' (1970).
1965's 'Galaxy 4', 1967's 'The Evil of the Daleks' and the same year's 'The Ice Warriors' were his other three contributions.
Born on April 4, 1931, Martinus studied at Yale Drama School and worked as an actor, before turning his attentions to a career as a director.
His credits include episodes of Blakes 7 and Z Cars and award-winning children's drama The Paper Lads.
Doctor Who director Christopher Barry dies, aged 88
Watch a clip from 'Spearhead From Space' below: