Quiz

He played Potter in both Koroshi (1967), and The Girl Who Was Death (1968) (which both starred Patrick McGoohan). This lends credence to the theory held by some that McGoohan's character in the earlier series (and it's 1/2-hour iteration) is the same person as Number Six. Although McGoohan, who was the co-creator, producer and frequent writer of Il prigioniero (1967), has repeatedly said (publicly) it wasn't his intention, and 'wished another actor had played Number Six. It's also common knowledge that had he confirmed this, it would've opened him up to having to (financially) compensate Gioco pericoloso (1964), series creator, Ralph Smart for this.

He is one of only 31 performers to have acted in both the 20th Century Doctor Who TV series and the 21st Century Doctor Who TV series.

In addition to his three appearances in Doctor Who, he was on the shortlist for Toby (played by Windsor Davies) in The Evil of the Daleks: Episode 2 (1967) and the main guest role of Professor Marcus Scarman (played by Bernard Archard) in Pyramids of Mars: Part One (1975).