The mummified body of Egyptian pharaoh Tutankhamun spontaneously combusted after a botched attempt to embalm him, according to scientists in a new documentary.

A fragment of flesh from the boy pharaoh, whose tomb was discovered in the Valley of the Kings in 1922 by Howard Carter and the Earl of Carnarvon, was tested by researchers who confirmed that the body was burned while sealed in his coffin.

Fire investigators, featured in a new Channel 4 documentary, believe a chemical reaction caused by embalming oils used on Tutankhamun's mummy sparked the blaze.

The discovery of his nearly intact tomb, complete with a gold coffin and gold funeral mask, pictured, was a worldwide sensation and sparked huge public interest in ancient Egypt.

Egyptologist Dr Chris Naunton examined Carter's original notes and also carried out a virtual autopsy of the body using X-ray and CT scanning technology which he said pointed to a theory that the young ruler died in battle.