Nigel Patrick as Superintendent Robert Hazard

Michael Craig as Inspector Phil Learoyd

Yvonne Mitchell as Mildred

Paul Massie as David Harris

Bernard Miles as Ted Harris

Olga Lindo as Mrs. Harris

Earl Cameron as Dr. Robbins

Gordon Heath as Paul Slade

Barbara Steele as Student

Peter Vaughan as Detective Whitehead (uncredited)

Yvonne Buckingham as Sapphire Robbins

Jocelyn Britton as Patsy

Robert Adams as Horace Big Cigar

Desmond Llewelyn as Police Constable

Fenella Fielding as Lingerie Shop Manageress

Susan Stranks as Student

Freda Bamford as Sgt. Cook

Rupert Davies as Ferris

Orlando Martins as Barman

Harry Baird as Johnnie Fiddle

Grace Arnold as Sapphire's Landlady

Thomas Baptiste as Man on the Street

Victor Brooks as Police Sgt.

Basil Dignam as Doctor Burgess

Dorothy Gordon as Lily

Nora Gordon as Newsagent's Wife

Lucy Griffiths as Johnnie Fiddle's Landlady

Vanda Hudson as Girl at Tulip Club

Dan Jackson as Nightclub Owner

Philip Lowrie as Student

Bartlett Mullins as Newsagent

Philip Ray as Mr. Young

Lloyd Reckord as Pianist in International Club

John Richardson as Student

Richard Vernon as Doctor at Crime Scene

Christopher Witty as Boy

Dolores Mantez as Student (International Club)

Anthony Singleton as Bit Part

Geremy Phillips as Youth

Joan Hooley as Woman in Street

Boscoe Holder as Dancer in Nightclub

George Curtis as Police Constable