Eric Portman as Paul Mangin

Edana Romney as Mifanwy

Barbara Mullen as Veronica

Hugh Sinclair as Owen Rhys

Bruce Belfrage as Sir David Conway

Joan Maude as Caroline Hart

Leslie Weston as Mortimer

Alan Wheatley as Edgar Orsen

Hugh Latimer as Bing

John Penrose as Brandy

Christopher Lee as Charles

Lois Maxwell as Lois

Mavis Villiers as Babs

Thora Hird as Visitor in Tussauds

Valentine Dyall as Counsel for the Defence (uncredited)

Susanne Gibbs as Gwendoline (uncredited)

Noel Howlett as Psychiatrist (uncredited)

Gordon McLeod as Public Prosecutor (uncredited)