Cambridge spy Guy Burgess’ briefcase and passport on display at MI5: Official Secrets exhibition

A briefcase left behind by infamous Cambridge spy Guy Burgess as he fled to Moscow in 1951 is among never-before-seen MI5 artefacts going on display at The National Archives in Kew, South-West London.

The MI5: Official Secrets exhibition, which features objects from MI5’s private collection alongside declassified documents, marks the first time the intelligence agency has ever collaborated to display its files to the public.

Director General of MI5, Sir Ken McCallum, said the exhibition is part of the Security Service’s “ongoing commitment to being open wherever we can”.

Among the highlights is a leather briefcase, inscribed with initials and left at the Reform Club in London by Cambridge spy Guy Burgess as he fled to Moscow in May 1951.

His British passport has also been displayed for the first time.

Burgess was a British diplomat and Soviet double agent during the Second World War and the early Cold War period.

He was a member of the Cambridge Five spy ring and fled to Moscow with fellow spy Donald Maclean in 1951 due to fears of being discovered.

None of the Cambridge Five was ever prosecuted for spying.

Another key exhibit is a 110-year-old lemon used as evidence against German spy Karl Muller.

Muller used lemon juice as invisible ink to inform on British troop movements. A warm iron was passed over a letter to reveal the secret messages.

When he was arrested, the lemon was found in his overcoat. He was executed by firing squad at the Tower of London in 1915.

Speaking at a preview of the exhibition, the MI5 Director General said: “Having worked for MI5 for nearly 30 years I can tell you that the reality of our work is often different from fiction. Whether that fiction is George Smiley or Jackson Lamb.

“MI5 life is about ordinary human beings together doing extraordinary things to keep our country safe. Some of their stories and their perspective comes through in this exhibition.

“And while much of our work must remain secret, what you will see today reflects our ongoing commitment to being open wherever we can. And not just about our glorious moments.”