 Jack WarnerMaj. Alec White | Maj. Alec White |
 Nigel PatrickInsp. Michael Kenyon | Insp. Michael Kenyon |
 Elizabeth SellarsRita Compton | Rita Compton |
 Terence MorganRoger Compton | Roger Compton |
 Greta GyntMme. Simonetta | Mme. Simonetta |
 Theodore BikelMax | Max |
 Eric PohlmannSteven Lasovich | Steven Lasovich |
 Joyce GrenfellLady Flavia Queensway | Lady Flavia Queensway |
 Michael HordernDirector of Customs | Director of Customs |
| JJames GilbertAgent Larkins | Agent Larkins |
 Martin BoddeySub-Director Holt | Sub-Director Holt |
 Hal OsmondBaggage Room Clerk | Baggage Room Clerk |
 Jacques BruniusDet. Pierre Valance | Det. Pierre Valance |
 Ronald AdamMr. Bennett | Mr. Bennett |
 Jill AdamsMichael's Dance Partner (uncredited) | Michael's Dance Partner (uncredited) |
 John ArnattCustoms Officer (uncredited) | Customs Officer (uncredited) |
 Ballard BerkeleyCooper | Cooper |
 Jacques CeyLittle Frenchman | Little Frenchman |
 Cyril ChamberlainCustoms Officer | Customs Officer |
| PPhilip DaleA.P.O. | A.P.O. |
 David Davies(uncredited) | (uncredited) |
| GGuy De MonceauHead Waiter (uncredited) | Head Waiter (uncredited) |
 Arnold DiamondFrench Customs Officer | French Customs Officer |
 Tom GillMontana Hotel Receptionist | Montana Hotel Receptionist |
| CCampbell GrayLuigi | Luigi |
| GGeorge HilsdonPolice Driver (uncredited) | Police Driver (uncredited) |
 John HorsleyCustoms Officer | Customs Officer |
 Robin HunterA.P.O. | A.P.O. |
 Douglas IvesSeaman | Seaman |
| HHamilton KeeneCop at London Airport | Cop at London Airport |
