He has performed with the Royal Shakespeare Company.
He was on the shortlist for "Toby" (played by Windsor Davies ) in "Doctor Who" (1963): The Evil of the Daleks.
One of only 26 performers to have acted in both the 20th Century Doctor Who TV series and the 21st Century Doctor Who TV series.
Played the same character (Potter) in "Secret Agent" (1964) and "The Prisoner" (1967), both of which starred Patrick McGoohan. This lends credence to the belief that McGoohan's "Danger Man" (1960) and "Secret Agent" (1964) character, John Drake, is the same person as Number Six, the character he later portrayed in "The Prisoner" (1967) although McGoohan, who was also the co-creator, producer and frequent writer of the later series, claims that this was never his intention.
Served in the Royal Air Force.