Queen Elizabeth II was not officially informed for almost a decade that one of her most senior courtiers had confessed to being a Soviet spy, according to newly released MI5 files.

Anthony Blunt, who worked at Buckingham Palace as Surveyor of the Queen’s Pictures, was secretly a Soviet spy during WWII.

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.

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

Queen Elizabeth II was not officially informed for nearly a decade that Anthony Blunt was a Soviet spy, newly declassified documents reveal.