The only known wartime footage showing the lives of secret spies during theSecond World War has been donated to the Bletchley Park Trust.
The rare 11-minute silent film shows members of MI6 section eight at Whaddon Hall, Buckinghamshire, where top-secret decrypted messages from codebreakers based at Bletchley Park would be sent and then passed on to Allied commanders in the field.
Due to the intense secrecy of the work at Bletchley Park and its associated sites, photography and film were banned.
The film shows the personal lives of the men and women at Whaddon Hall while off-duty, with footage of the Whaddon hunt, a football game and a cricket match.
Dr David Kenyon, research historian at Bletchley Park, said: "No other filmfootage of a site intimately connected with Bletchley Park exists.
"We don't know who filmed it and the footage doesn't give away any statesecrets or any clues about the work the people in it are doing.
"If it fell into the wrong hands, it would have given little away, but for us today it is an astonishing discovery and important record of one of the most secret and valuable aspects of Bletchley Park's work."
Watch Bletchley Park's video on the story behind the footage (Credit: Bletchley Park).
The reel of wartime footage, preserved in its original canister, was donated to Bletchley Park by an anonymous donor.
The footage was shown to war veteran Geoffrey Pidgeon, who started working for MI6 section eight when he was 17-years-old.
The film includes the only known film footage of Geoffrey's father Horace "Pidge" Pidgeon, who also worked at Whaddon Hall from July 1940 to December 1945.
"I'd never seen my father on a cinefilm before," said Mr Pidgeon. "I was very surprised and moved to watch it for the first time, it's a remarkable find."