Harry Fowler later married fellow actress Joan Dowling, but sadly she committed suicide in 1954, aged just 26.
A piece of graffiti seen during the title sequence reads "Corny is a rotter", an in-joke reference to associate producer Henry Cornelius whose nickname was 'Corny'. This reference was possibly heartfelt as Cornelius was a hard-driving perfectionist.
The plot involves the non-existence of the vehicle registration mark GZ used by the crooks. This did in fact exist at the time, but it was in use in Belfast. It might have been seen in London, but would have been very unusual.
The bus which Joe Kirby jumps onto after buying a copy of The Trump is registration JJ4377. The same bus is seen twice later in the film, passing outside the publishers of The Trump and was obviously hired from London Transport for the exterior shots.