Det. Chief Insp. Hawkins (149 episodes)

Det. Chief Supt. Watt (149 episodes)

Det. Sgt. Evans (149 episodes)

PC Snow (7 episodes)

PC Henry Snow (3 episodes)

Chief Constable Cullen (6 episodes)

Chief Constable Arthur Cullen (3 episodes)

Insp. Armstrong (7 episodes)

Det. Chief Supt. Barlow (6 episodes)

Det. Chief Supt. Charles Barlow (1 episode)

Technician (uncredited) (1 episode)

Keith Brogan (1 episode)

Detective (uncredited) (1 episode)

Driver (uncredited) (1 episode)

Bertie Cooper (1 episode)

Outwood (1 episode)

Frank Mason (1 episode)

Lodge (1 episode)

Edward Letheridge (1 episode)

Professor Dowell (1 episode)

Derek Watson (1 episode)

Bruton (1 episode)

Jameson (1 episode)

PC Drake (2 episodes)

Det. Sgt. Grant (2 episodes)

Chief Immigration Officer Ingrams (1 episode)

Civil Servant (1 episode)

Somers (1 episode)

Mrs. Lacey (1 episode)

Chief Supt. Ted Leach (1 episode)

Roy Simpkins (1 episode)

Stephens (1 episode)

Daley (1 episode)

Cranley (1 episode)

Mrs. Harrison (1 episode)

Jennings (1 episode)

Red Rayner (1 episode)

Stackpole (1 episode)

Norden (1 episode)

Johnny Hicks (1 episode)

Maggie Grant (1 episode)

Paul Ashworth (1 episode)

Danny Fitch (1 episode)

Morry Fine (1 episode)

Maitland (1 episode)

Mr. Fordham (1 episode)

Councillor Fordham (1 episode)

James Potter (1 episode)

Samuel Tomkins (1 episode)

Tate (1 episode)

William Ross (1 episode)

Tom Price (1 episode)

Billet (1 episode)

Chris Stroud (1 episode)

Jackson (1 episode)

Jackie Turner (1 episode)

Martin Webb (1 episode)

Det. Chief Supt. Allan (1 episode)

Jack Davis (1 episode)

Collins (1 episode)

Mitchell (1 episode)

Jane Rawlings (1 episode)

Dr. Tadman (1 episode)