He featured in the spoof James Bond sequence shown at the London 2012 Olympics, greeting 007 star Daniel Craig at Buckingham Palace and introducing him to the Queen, before accompanying them along a corridor with the corgis.

In 1982, he apprehended the intruder Michael Fagan who had broken into the Queen’s bedroom at the Palace, with the footman congenially distracting him by offering him a drink and serving him a whisky.

Mr Whybrew is working two days a week on the project, using gloves to protect the papers as he sifts through letters and correspondence.

He is part of a team from the Master of the Household’s Department and the Royal Collection Trust.

The late Queen’s wardrobe is among the other items which require cataloguing, but it is understood that Angela Kelly, who was Elizabeth II’s confidante and senior dresser for many years and has since moved out of the Windsor estate, is not currently involved.

Mr Whybrew was made a Commander of the Royal Victorian Order (CVO) for his service in Elizabeth II’s demise honours following her death, and he took part in ceremonial processions on the day of her funeral.

Buckingham Palace declined to comment.