"An actor is murdered live on air whilst a play is being broadcast. Everyone in the play and broadcasting house fall under suspicion."
Ian Hunter
as Detective Inspector Gregory
Austin Trevor
as Leopold Dryden
Lilian Oldland
as Joan Dryden
Henry Kendall
as Rodney Fleming
Val Gielgud
as Julian Caird
Peter Haddon
as Guy Bannister
Betty Ann Davies
as Poppy Levine
Jack Hawkins
as Herbert Evans
Donald Wolfit
as Sydney Parsons
Robert Rendel
as Sir Herbert Farquharson
Gordon McLeod
as Chief Commissioner
Hannen Swaffer
as Hannen Swaffer
Vernon Bartlett
as Vernon Bartlett
Eric Dunstan
as Eric Dunstan
Gillie Potter
as Gillie Potter
Elisabeth Welch
as Elisabeth Welch
Eve Becke
as Eve Becke
Gershom Parkington
as Gershom Parkington
Percival Mackey
as Percival Mackey
Ivor Barnard
as Joseph Higgins (uncredited)
Cecil Bevan
as Police Doctor (uncredited)
George De Warfaz
as Foreigner (uncredited)
Howard Douglas
as Weisskopf (uncredited)
Arthur Hambling
as Man on BBC Reception Desk (uncredited)
Vincent Holman
as Detective (uncredited)
Bruce Lester
as Peter Ridgwell (uncredited)
Percy Rhodes
as Wife's Lover on Broadcast (uncredited)
Reginald Denham
Director
Günther Krampf
Director of Photography
R. Holmes Paul
Art Direction
Reginald Beck
Editor
Colin Becke
Costume Design
Basil Mason
Adaptation
Novel
Vincent Permane
Assistant Director
John Cox
Sound Recordist
Hugh Perceval
Production Supervisor
Eric Maschwitz
Geoffrey Goodheart
Music Director
Ord Hamilton
Original Music Composer