Inspector Duval comes to London to help crack the case of a socialite murdered during a jewel heist.
| Writing | Jacques Monteux | Story |
| Writing | J. Henry Piperno | Writer |
| Camera | Stephen Dade | Director of Photography |
| Editing | Oswald Hafenrichter | Editor |
| Directing | Max Varnel | Director |
| Production | Kay Luckwell | Production Supervisor |
| Art | Tony Inglis | Art Direction |
| Sound | Wilfred Burns | Original Music Composer |
| Production | Richard F. Dalton | Production Manager |
| Directing | Bill Snaith | Assistant Director |
| Camera | Gus Drisse | Camera Operator |
| Directing | Doreen Soan | Continuity |
| Sound | Brendan Redmond | Sound Recordist |
| Costume & Make-Up | Eileen Long | Wardrobe Master |
| Costume & Make-Up | Celia Bennett | Hairstylist |
| Production | Barbara Rowland | Production Secretary |
| Production | Bill Luckwell | Producer |
| Production | Jock MacGregor | Producer |