Campbell Singer (16 March 1909 - March 1976) was a British character actor who featured in a number of film and television roles during his long career.He was a regular in British post-war comedy films, often playing policemen. He first appeared on television in 1946, making regular appearances in the following three decades including several episodes of 'Hancock's Half Hour', and played the lead, John Unthank, in the BBC drama series 'Private Investigator' in 1958/9.