The to-let sign outside the house occupied by the nefarious Corbeck bears the company name Neame and Skeggs, named for the film's production manager and production supervisor, Christopher Neame and Roy Skeggs, respectively.
The UK cinema version was cut by the BBFC to remove a shot of George Coulouris being struck across the face by male nurse James Cossins as there was public concern about the treatment of mental patients at the time.
Based on Bram Stoker's novel, 'Jewel of the Seven Stars.' You can see the seven stars (the Big Dipper) in many scenes throughout the production, either in crystal balls, ruby rings.