Voice of the Whistler

Richard Dix

John Sinclair / John Carter

Acting

Lynn Merrick

Joan Martin Sinclair

Acting

Rhys Williams

Ernie Sparrow

Acting

James Cardwell

Fred (Doc) Graham

Acting

Tom Kennedy

Ferdinand / Hammerlock

Acting

Sam Ash

Gibson Motor Car Co. Executive (uncredited)

Acting

Egon Brecher

Dr. Rose (replaced by Frank Reicher) (uncredited)

Acting

Charles Coleman

Sinclair's Butler (uncredited)

Acting

Otto Forrest

The Whistler (uncredited)

Acting

Byron Foulger

Georgie (uncredited)

Acting

Martín Garralaga

Tony, Fruit Peddler (uncredited)

Acting

John Hamilton

Doctor (uncredited)

Acting