Movies:
* The Day of the Triffids (1962) - played "Bill Masen"
* The Wrong Box (1966) - played "Mr. Grogan"
* The Private Life of Sherlock Holmes (1970) - played "Dr. Watson"
* The Wicker Man (1973) - played "Sergeant Howie"
* The Last Starfighter (1984) - played "Centauri"
* The Lair of the White Worm (1988) - played "Professor James "Jim" Darrow"
* Highlander II: The Quickening (1991) - played "Father Sean"
* The Borrowers (1997) - played "Old Man"
* The Man Who Knew Too Little (1997) - played "Minister"
Television:
* Dr. Finlay's Casebook (1962-1971) - played "Sandy"
* The Adventures of Robin Hood (1955-1959) - played various roles
* The Saint (1962-1969) - played various roles
* The Avengers (1961-1969) - played various roles
* The Prisoner (1967-1968) - played "Number 6" in episode "Many Happy Returns"
* Dixon of Dock Green (1955-1976) - played various roles
* The Sweeney (1975-1978) - played "Terry the Chinaman"
* The Professionals (1977-1983) - played "Jacko"
* The Bill (1984-2010) - played various roles
* Taggart (1983-2010) - played various roles
* Coronation Street (1960-2010) - played various roles
* EastEnders (1985-2010) - played various roles
* Heartbeat (1992-2010) - played various roles
This is not an exhaustive list, but it includes some of his most well-known and memorable roles. He was a versatile character actor who appeared in numerous films and television shows, playing a wide range of characters.
For a more complete list of his works, you can consult databases like IMDb.