The files about royal art historian Anthony Blunt are among a trove from the intelligence agency MI5 released Tuesday by Britain’s National Archives.

Documents newly declassified by MI5, Britain's internal intelligence agency, show the late Queen Elizabeth II was not informed for almost 10 years that a member of her staff had spied for the then-Soviet Union.

Newly declassified files reveal the late Queen's very unexpected reaction to the art historian's shocking secret.

Documents from the British secret service MI5 reveal that Anthony Blunt, an art historian and supervisor of the official Royal Art Collection, was actually a member of the notorious spy organisation Cambridge Five,

Sir Anthony Blunt, the royal family's picture surveyor and renowned art historian, finally admitted that he had been a Soviet agent since the 1930s