Sapphire

Nigel Patrick

Superintendent Robert Hazard

Michael Craig

Inspector Phil Learoyd

Yvonne Mitchell

Mildred

Paul Massie

David Harris

Bernard Miles

Ted Harris

Olga Lindo

Mrs. Harris

Earl Cameron

Dr. Robbins

Gordon Heath

Paul Slade

Barbara Steele

Student (uncredited)

Peter Vaughan

Detective Whitehead (uncredited)