Mike Pratt (Jeff Randall) spends a lot of time sitting down in this episode and a very obvious double, even from behind, is seen walking around in his place. This is due to the fact that while filming this episode, Mike Pratt had gone out celebrating his birthday and climbed a lamp post to get in to his apartment because he'd lost his keys. He subsequently fell and broke both his legs. In the final episode (The Ghost Talks) filmed immediately after this one, Jeff Randall is in a hospital bed with both legs in plaster where it is discussed that he fell from a balcony chasing a crook. His lines were then given to Kenneth Cope (Marty Hopkirk) and it was rewritten as a flashback episode with Marty recalling a case he worked on while Jeff was on another case in Scotland.
In the second series of Supercar (1961), guest actor Cyril Shaps (Dr Cholmond) had inherited the character of Masterspy and Professor Popkiss, previously played by George Murcell (Mandrake).
The football match feautured is the England v West Germany 1966 World Cup Final.
In this episode Martha (Patricia Haines) marries Mandrake (George Murcell). In real life Patricia Haines was married to Bernard Kay, who played Dighton, the undertaker in this story.