Queen Elizabeth II wasn’t told details of her long-time art adviser's double life as a Soviet spy because palace officials didn’t want to add to her worries, newly declassified documents reveal.

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.

Members of the spy ring in the 1930s spilled secrets to the Soviet Union from the heart of the U.K. intelligence establishment.

Art historian Anthony Blunt was for decades Surveyor of the Queen's Pictures, overseeing the official Royal Art Collection, and in 1964 admitted he had been a Soviet agent since t