Mystery surrounds a copy of a death sentence letter issued by the Irgun in one of Mandate Palestine’s most controversial episodes. It was found in a house in Hampshire.

The written statement, dated July 30 1947, is thought to be a contemporary copy of the judgment placed on the bodies of Sergeants Clifford Martin and Mervyn Paice. The British officers were hanged by Irgun in an attempt to free fellow Jewish fighters who were eventually executed by the British.

The Irgun attack, known as the Sergeants Affair, was condemned as a “crime” by Anglo-Jewry at the time, but nevertheless sparked antisemitic riots against British Jews in Liverpool, London and Glasgow. Businesses were attacked with bricks, and a synagogue in Derby was burned down.

Hampshire auction house George Kidner said the letter was uncovered in a house clearance of a nearby home, and plans to sell the letter on March 7.

Kidner’s auctioneer Edward Cowell, an expert in militaria, said the letter may have been a British military copy or one made for propaganda purposes during the height of the controversy.

“The link to its origins has been irrevocably lost so there is no way of tracing how the letter turned up in a private home. We know who owned it but we do not know any military connection.

“Whether it is a singular, private copy or something that was produced for circulation is unclear, though I have not found word of any other examples.”

The item is valued at just £10, but is expected to generate greater interest.