Gavin Cordon

Newly-declassified files show notorious double agent refused ‘insane' order to follow fellow spies Burgess and Maclean to Moscow.

The guidance is contained in a booklet issued to all new recruits to the Security Service during the Second World War.

Newly-declassified files show the Queen was only told the full story a decade after royal courtier confessed to spying for the KGB.

Newly declassified files show the moment the notorious Cambridge double agent finally confessed to his treachery.

MI5's top interrogator was baffled by Kim Philby, admitting he could not determine whether he was a Soviet spy, according to newly declassified intelligence files.

Film star Dirk Bogarde was warned by MI5 that he could be the target of a gay “entrapment” attempt by the KGB, according to newly-declassified intelligence files.

Newly released files show the agency’s top interrogator could not determine whether Philby was a Russian spy.

The guidance will feature in a new exhibition at the National Archives focusing on the work of the Security Service.

The identity of a Russian spy among Queen Elizabeth II's courtiers was kept from the monarch for almost a decade, but she took the news with her typically calm demeanour

In 1964, Sir Anthony Blunt, who was the Royal Family's picture surveyor and a famous art historian, admitted he had been a Soviet agent since the 1930s