British crime film directed by Peter Duffell and starring Bernard Lee, Moira Redmond and John Van Eyssen, loosely based on the 1918 novel "The Man Who Knew" by Edgar Wallace.
| Actor | Role |
|---|---|
 Bernard LeeInspector Mann | Inspector Mann |
 Moira RedmondFreda Strickland | Freda Strickland |
| SStanley MorganSergeant Rutledge | Sergeant Rutledge |
 John Van EyssenMerril | Merril |
| GGordon BoydRex Holland | Rex Holland |
| MMark SingletonShilton | Shilton |
| VVictor PlattHarold Strickland | Harold Strickland |
 Ernest ClarkAshton | Ashton |
 Nicholas SmithPawn Shop Assistant | Pawn Shop Assistant |
 Larry MartynPete Lake | Pete Lake |
| DDanny SewellAvery | Avery |
| RRobert SansomDoctor | Doctor |
| RRichard ShawBill Cross | Bill Cross |
| GGraham LeamanBallistics Scientist | Ballistics Scientist |
| HHilary MartynRita | Rita |
| CClive MarshallTony Hart | Tony Hart |
| RRuth MeyersMary Nuttal | Mary Nuttal |
| DDeidre DaySecretary | Secretary |
| PPeter Howard-JohnsonPolice Sergeant | Police Sergeant |