Neil McCallum

From Wikipedia:

Neil John McCallum (1929–1976) was a British-Canadian actor. After attending the Guildhall School of Music and Drama in London, McCallum's first major appearance on stage was alongside Sam Wanamaker in The Rainmaker in the mid-1950s. He appeared in British TV series in the 1950s, 1960s and early 1970s, including The Saint, Department S and UFO, and in films such as The Siege of Pinchgut (1959) and Dr. Terror's House of Horrors (1965). He provided the voices of Dr Ray Pierce in the film Thunderbirds Are Go (1966) and an airport controller in the TV series Captain Scarlet and the Mysterons (1967). He played lead character Angelo James in the BBC TV series Vendetta (1966-68).

He was also a scriptwriter (scripting two 1964 thrillers, Do You Know this Voice? and Walk a Tightrope, among other things), a producer and occasional director.