Five Cambridge University graduates served as double agents, leaking highly classified information to the Soviet Union

The newly-declassified documents include details about some of the UK's most notorious spies.

Blunt was recruited by MI5 during World War II but the secret services became suspicious of him after Guy Burgess and Donald Maclean, whom he had been close friends with since their days at Cambridge University in the 1930s, defected to Russia in 1951.

Top secret MI5 files detailing first-hand accounts of confessions of three of Britain's most notorious double agents including Kim Philby and Anthony Blunt who spied for the Soviet Union were released for the first time on Tuesday.

The National Archives has released declassified MI5 files, including the confession of a civil servant who worked in the Cabinet Office, Treasury and Foreign Office in the 1930s, 1940s and 1950s – and spied for the Soviet Union at the same time.

Newly declassified British documents show that 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 worr

MI5 documents reveal her private secretary ‘saw no advantage in telling her’ about treachery of Buckingham Palace art expert

MI5 reveals confessions of three members of infamous Cambridge Five spy ring as tranche of documents released into National Archives

Queen Elizabeth II was not told about her long-time art adviser's double life as a Soviet spy, newly declassified documents reveal.

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.

Queen Jetsun Pema and King Jigme Khesar Namgyel Wangchuck of Bhutan, often called ‘most attractive’ royal couple in the world, honoured Steve Jobs' widow for her ‘extraordinary contributions to the be

Former aide of late Queen Elizabeth II, Anthony Blunt, worked as spy for the Russia for almost 10 years without the queen knowing about it.