THE key to Napoleon’s prison bedroom is going under the hammer after it was unearthed in a trunk in Scotland.

The 13cm key was used to unlock the room where the French emperor died in 1821, on the island of St Helena where he was in exile as a British prisoner.

Charles Richard Fox, a “military man”, was on St Helena and brought the key back home. He gave it to his mother, Baroness Holland, a “superfan” of the French former ruler, who sent Napoleon books and sweetmeats.

Her descendants have unpacked the key and are now auctioning it.

David Macdonald, from Sotheby’s, said: “The family always knew it was around but it was tucked away.”

The key will go under the hammer with Fox’s note identifying it. The items are expected to fetch £5000 in an online sale which closes for bidding on Thursday.