Rex Carver
Rex Carver is a fictional British private eye created by the prolific writer Victor Canning. He appeared in four fast-paced, irreverently narrated novels in the 1960s.
In the book preceding the novels, The Limbo Line (1963), the Government agency that Carver is unwillingly drawn into is described for the first time. It introduces Richard Manston, a retired agent drawn back into the world of spies, who also appears as a character in some of the later Rex Carver books.
Although strictly a private investigator, Carver knows a number of people who work for a shadowy British undercover agency and he frequently runs into both enemy agents and hostile British agents during his adventures. It is by no means a stretch to call his adventures spy thrillers or to consider Carver himself a secret agent of sorts.