Det. Supt. Robert Fabian (37 episodes, 1954-1956)
Det. Sgt. Wyatt / Detective Sergeant / Detective Sims / Frankie (14 episodes, 1954-1955)
Detective Sergeant (6 episodes, 1954-1956)
Expert / Wood Expert / Metal Expert / Typewriter Expert (6 episodes, 1954-1956)
Laboratory Expert / Pathologist / Microbiologist (5 episodes, 1955-1956)
Graphologist / Fat Harry / Police Surgeon (4 episodes, 1955)
Psychiatrist / Pathologist (4 episodes, 1955)
Sergeant MacKenzie (3 episodes, 1954-1955)
Jeremiah Rugeley / Vicar (3 episodes, 1955)
Supervisor (3 episodes, 1955-1956)
Nicholas Bardwell / Harry Disbrow (3 episodes, 1955)
Mr. Kinney / Padlane / Pinkley (3 episodes, 1955)
Kate Hubble / Mary Sedney / Mollie Boldero (3 episodes, 1954-1955)
Pathologist / Police surgeon (3 episodes, 1954-1955)
Angela Hollis / Mary Soong / Sara Milne (3 episodes, 1955)
Cynthia Barker / Lily Ransome / Silvara (3 episodes, 1955)
Edna Kent / Jane / Monica Ridley (3 episodes, 1955)
Mrs. Barker / Mrs. Brownlove / Mrs. Wagner (3 episodes, 1955)
Helen Kervan / Janet Tedford (2 episodes, 1955-1956)
Mr. Porter / Vale (2 episodes, 1955)
Lady Jane Shaw / Marion Courtland (2 episodes, 1955)
Doris Tedford / Mrs. Regis (2 episodes, 1954-1955)
Assistant Commissioner / Prison Governor (2 episodes, 1954-1955)
Charlie / Detective Sergeant (2 episodes, 1954-1955)
Mac / Sandy Evans (2 episodes, 1956)
Mrs. Manners / Mrs. Mitchell (2 episodes, 1956)
Mrs. Boody / Mrs. Flinge (2 episodes, 1955)
Map Expert (2 episodes, 1956)
Detective Sergeant / Sergeant (2 episodes, 1954-1955)
Forgery Expert (2 episodes, 1954-1955)
Jerry Watson (2 episodes, 1955-1956)
Roger Garven / Ted Enfield (2 episodes, 1955)
Carlac / Sen Shan (2 episodes, 1955)
Bill Jaggers / James Ridley (2 episodes, 1955)
Jim Graham / Trew (2 episodes, 1955)
Blackie / Cox (2 episodes, 1955)
Mr. Wimpole / Professor Hughes (2 episodes, 1955)
Mrs. Dove / Tessa Oakman (2 episodes, 1955)
Arthur Flagg / Nobby (2 episodes, 1955)
Self - Closing Statements (1 episode, 1955)
Museum Custodian (2 episodes, 1956)
Mitchell / Roger Kervan (2 episodes, 1956)
Policewoman Wetherby (1 episode, 1954)
Sgt. Jim Jarvis (1 episode, 1955)
Carl Paxton (1 episode, 1954)
Ken Masters (1 episode, 1955)
Mrs. Masters (1 episode, 1955)
Julie (1 episode, 1956)
Child (1 episode, 1955)
Professor Wynn Jones (1 episode, 1955)
Jim Keyes (1 episode, 1955)
Superintendent Forbes (1 episode, 1955)
Madame Amata (1 episode, 1956)
Schoolmistress (1 episode, 1955)
Dutchy (1 episode, 1955)
Railway Foreman (1 episode, 1956)
Nick (1 episode, 1955)
The Doctor (1 episode, 1955)
Ellie Stafford (1 episode, 1954)
Chick (1 episode, 1954)
Elstead (1 episode, 1954)
The Actress (1 episode, 1954)
Vera Proudly (1 episode, 1954)
Captain Pool (1 episode, 1954)
Hagben (1 episode, 1954)
Mrs. Wilkins (1 episode, 1954)
Ballistics expert (1 episode, 1954)
Mona Proudly (1 episode, 1954)
Dan Stafford (1 episode, 1954)
Police Superintendent (1 episode, 1954)
Nanny (1 episode, 1954)
Rose Pool (1 episode, 1954)
Aunt Bess (1 episode, 1954)
Colonel Ledbetter (1 episode, 1954)
Arthur Carlton (1 episode, 1954)
Susan (1 episode, 1955)
(1 episode, 1955)
Tom (1 episode, 1955)
Heywood (1 episode, 1955)
Emma Horton (1 episode, 1955)
Audley / Brownlove (1 episode, 1955)
Night Club Owner (1 episode, 1955)
Big Fred (1 episode, 1955)
Dock Worker (1 episode, 1955)
Agatha (1 episode, 1955)
Sir Digby Button (1 episode, 1955)
Doctor (1 episode, 1955)
Dr. Brighton (1 episode, 1955)
Jerry Strong (1 episode, 1955)
Ronald James (1 episode, 1955)
Ambassador (1 episode, 1955)
Sergeant (1 episode, 1955)
Mary Walton (1 episode, 1955)
Cora (1 episode, 1955)
Helen Russell (1 episode, 1955)
Girl (1 episode, 1955)
Selby (1 episode, 1955)
Pawnbroker (1 episode, 1955)
Inspector Kelson (1 episode, 1955)
Peggy Drayton (1 episode, 1955)
Lady Edith Garven (1 episode, 1955)
Mr. Barker (1 episode, 1955)
Spicer (1 episode, 1955)
Sylvia Parker (1 episode, 1955)
Mr. Pontifex (1 episode, 1955)
Andy Wagner (1 episode, 1955)
Larry Redman (1 episode, 1955)
Detective Sergeant (1 episode, 1955)
Heathrow (1 episode, 1955)
Amanda Malloy (1 episode, 1955)
Dr. Walton (1 episode, 1955)
Fleddon (1 episode, 1955)
Popes (1 episode, 1955)
Dr. Horn (1 episode, 1955)
Mrs. Daisy (1 episode, 1955)
Mrs. Apsley (1 episode, 1955)
Mrs. Mortlake (1 episode, 1955)
Mary (1 episode, 1955)
Mr. Thrale (1 episode, 1955)
Deborah (1 episode, 1955)
Sir Michael Garven (1 episode, 1955)
George Hubble (1 episode, 1955)
Quailes (1 episode, 1955)
Madden (1 episode, 1955)
Frieda Barnes (1 episode, 1955)
Ruth (1 episode, 1955)
Yard Expert (1 episode, 1955)
Eddie Carmen (1 episode, 1955)
Ellen (1 episode, 1955)
Police Superintendent (1 episode, 1955)
Rita (1 episode, 1955)
Bill Beckford (1 episode, 1955)
Major Randall (1 episode, 1955)
Minlane (1 episode, 1955)
Peter Lanceford (1 episode, 1955)
Expert (1 episode, 1955)
Waitress (1 episode, 1955)
Robert Meekers (1 episode, 1955)
Teresa (1 episode, 1955)
City Sergeant (1 episode, 1955)
Robert Morley (1 episode, 1955)
Lois Russell (1 episode, 1955)
Carter (1 episode, 1955)
Maid (1 episode, 1955)
Dr. Cardwell (1 episode, 1955)
Jack Hollis (1 episode, 1955)
Mrs. Addison (1 episode, 1955)
Robbed woman (1 episode, 1955)
Turner (1 episode, 1955)
Chorus girl (1 episode, 1955)
Mrs. Ransome (1 episode, 1955)
Mrs. Flaxman (1 episode, 1955)
Peter (1 episode, 1955)
Policeman (1 episode, 1955)
Mr. Throgget (1 episode, 1955)
Miss Trilby (1 episode, 1955)
Ed Seddon (1 episode, 1955)
BOAC clerk (1 episode, 1955)
Chemist's assistant (1 episode, 1955)
Dalton (1 episode, 1955)
Barbara James (1 episode, 1955)
French Dancer (1 episode, 1955)
Student (1 episode, 1955)
Coker (1 episode, 1955)
Baines (1 episode, 1955)
Hon. Victor Leggett (1 episode, 1955)
Raynell (1 episode, 1956)
Galney (1 episode, 1956)
Kitty Penley (1 episode, 1956)
Chemist (1 episode, 1956)
Bateman (1 episode, 1956)
Magda (1 episode, 1956)
Radio Operator (1 episode, 1956)
(1 episode)
Palmer (1 episode)
Harry (uncredited) (1 episode, 1954)
Peter (uncredited) (1 episode, 1955)
Jane Masters (uncredited) (1 episode, 1955)