Frank Clifton Bossard (13 December 1912 – 19 June 2001) was a British Secret Intelligence Service officer who provided classified documents to the Soviet Union in the 1960s.

[5] Bossard married his first wife, Ethel Isobel Brash, on 26 February 1941 at St Simon's Parish Church, Southsea.

[7] He taught briefly at the Air Service College[8] before the Ministry of Aviation offered him a post as an assistant signals officer.

Soviet agents concluded that he had access to secret documents on guided missiles, had financial issues, and possessed multiple weaknesses of character.

Suspicions were confirmed when the Soviet double agent Dmitri Polyakov (known as TOPHAT) provided information about Bossard's activities.

[8][14] After weeks of surveillance and an investigation into his finances, Bossard was arrested on 12 March 1965 in the Ivanhoe Hotel in Bloomsbury, where he had been photographing documents.

[3][4] Bossard was charged with violating the Official Secrets Act[15] and received a trial at the Old Bailey on 10 May 1965, where he confessed[16] and was sentenced to 21 years in prison.

Lord Chief Justice Hubert Parker informed Bossard: "It would be longer, and I emphasise this, but for the fact that you are now 52 years of age and that you have shown a degree of remorse by making a full confession extending far beyond the matters in respect of which you are charged".

[19] After being released early from prison in 1975, Bossard changed his name to Frank Russell Clifton and found employment with Bird and Clarke, a firm of solicitors.