Detective Inspector Gregory
Leopold Dryden
Joan Dryden
Rodney Fleming
Julian Caird
Guy Bannister
Poppy Levine
Herbert Evans
Sydney Parsons
Sir Herbert Farquharson
Chief Commissioner
Hannen Swaffer
Vernon Bartlett
Eric Dunstan
Gillie Potter
Elisabeth Welch
Eve Becke
Gershom Parkington
Percival Mackey
Joseph Higgins (uncredited)
Police Doctor (uncredited)
Foreigner (uncredited)
Weisskopf (uncredited)
Man on BBC Reception Desk (uncredited)
Detective (uncredited)
Peter Ridgwell (uncredited)
Wife's Lover on Broadcast (uncredited)
