Générique complet
The Scarlet Clue
Sidney Toler
Charlie Chan
Benson Fong
Tommy Chan
Mantan Moreland
Birmingham Brown, Chauffeur
Robert Homans
Capt. Flynn
I. Stanford Jolley
Rolf Brot, alias Ralph Brett
Virginia Brissac
Mrs. Marsh
Jack Norton
Willie Rand
Janet Shaw
Gloria Bayne
Ben Carter
Ben Carter
Victoria Faust
Hulda Swenson / Janet Carter
Helen Deverell
Diane Hall
Leonard Mudie
Horace Karloss
Reid Kilpatrick
Mr. Chester, program announcer
Emmett Vogan
Mr. Hamilton
Crane Whitley
Henchman Cooper
Kernan Cripps
Detective (uncredited)
Charles Jordan
Nelson (uncredited)
Kenner G. Kemp
Police Radio Expert (uncredited)
Milton Kibbee
Herbert Sinclair (uncredited)
Frank Mayo
Det. Hodge (uncredited)
Leonard Mudie
Horace Karlos (uncredited)
Tom Quinn
Chemist (uncredited)
Charles Sherlock
Sgt. McGraw (uncredited)
Charles Wagenheim
Rausch (uncredited)
