An antique dealer believes that an ornate piece of wood he picked up at a car boot sale may be a 1,300-year-old artefact from the Crusades.

Christie's auction house in London is analysing the item after experts suggested that it could be the door of a tabernacle – a box used to carry and protect sacred texts – carried by the Knights Templar.

Measuring just ten inches by four inches, it is decorated with intricate military and religious images and is thought to date from between 700 and 1200AD.