Paul Carpenter as Larry Duke Rona Anderson as Katie Glebe Susan Shaw as Gina Harry Fowler as Monty Albright Robert Rietty as Roberto Paul Whitsun-Jones as Turk McNeil Sabrina as Trixie Alma Taylor as Nurse Sprott Patrick Jordan as Jack Lorrae Desmond as Singer Frank Thornton as Doctor Arthur Wontner as Sherlock Holmes Ian Fleming as Dr. Watson Lyn Harding as Professor Moriarty John Turnbull as Inspector Lestrade Robert Horton as Col. Ross Lawrence Grossmith as Sir Henry Baskerville Judy Gunn as Diana Baskerville Arthur Macrae as Jack Trevor Arthur Goullet as Col. Sebastian Moran Martin Walker as James Straker Eve Gray as Mrs. Mary Straker Gilbert Davis as Miles Stanford Minnie Rayner as Mrs. Hudson D. J. Williams as Silas Brown Ralph Truman as Bert Prince Ronald Shiner as Simpson the Stable Boy