Emrys Jones
— Robert Matthews / John Barlow
Zena Marshall
— Ann Farrington
John Horsley
— Inspector Clements
Joan Hickson
— Mrs. Fenton
Hector Ross
— Canning
Roger Maxwell
— Col. Hector Smythe
Marne Maitland
— Heinz
Ian Fleming
— Dr. Wilson
Frederick Piper
— Thomas Pritchard
George Pastell
— Ferrari
Lesley Deane
— Mrs. Smythe
Victor Platt
— Sergeant