Highly Dangerous

Margaret Lockwood

Frances Gray

Dane Clark

Bill Casey

Marius Goring

Commandant Anton Razinski

Naunton Wayne

Mr. Hedgerley

Wilfrid Hyde-White

Mr. Luke

Eugene Deckers

Alf

Olaf Pooley

Detective-Interrogator

Gladys Henson

Attendant

Paul Hardtmuth

Priest

Michael Hordern

Lab Director Owens

George Benson

Sandwich Stand Customer

Eric Pohlmann

Joe - the bartender

John Horsley

Customs Officer

Patric Doonan

Customs Man

Joan Haythorne

Judy

Jill Balcon

Wardress (uncredited)

Hyma Beckley

Café Mimosa Patron (uncredited)

John Boxer

Police Sergeant at Customs Café (uncredited)

Ernest Butcher

Tom - Lab Assistant (uncredited)

Daniel Brown

Train Passenger (uncredited)