Ian Hunter

Detective Inspector Gregory

Austin Trevor

Leopold Dryden

Lilian Oldland

Joan Dryden

Henry Kendall

Rodney Fleming

Val Gielgud

Julian Caird

Peter Haddon

Guy Bannister

Betty Ann Davies

Poppy Levine

Jack Hawkins

Herbert Evans

Donald Wolfit

Sydney Parsons

Robert Rendel

Sir Herbert Farquharson

Gordon McLeod

Chief Commissioner

Hannen Swaffer

Hannen Swaffer

Vernon Bartlett

Vernon Bartlett

Eric Dunstan

Eric Dunstan

Gillie Potter

Gillie Potter

Elisabeth Welch

Elisabeth Welch

Eve Becke

Eve Becke

Gershom Parkington

Gershom Parkington

Percival Mackey

Percival Mackey

Ivor Barnard

Joseph Higgins (uncredited)

Cecil Bevan

Police Doctor (uncredited)

George De Warfaz

Foreigner (uncredited)

Howard Douglas

Weisskopf (uncredited)

Arthur Hambling

Man on BBC Reception Desk (uncredited)

Vincent Holman

Detective (uncredited)

Bruce Lester

Peter Ridgwell (uncredited)

Percy Rhodes

Wife's Lover on Broadcast (uncredited)