A medical scan of King Tutankhamun's mummified corpse may have finally nailed the cause of the Egyptian pharaoh's premature death.
It was not a blow to the head, as some have speculated, but gangrene caused by a badly broken leg.
Radiologists used a sophisticated 3D x-ray of Tutankhamun's body to identify what may have happened to the boy king before he died 3300 years ago at about the age of 19.
Computed tomography (CT) scans of the pharaoh's mummy, presented to the annual meeting of the Radiological Society of America in Chicago, confirmed a possible fracture in the youth's femur, or thigh bone, which probably occurred just before he died.
Ashraf Selim, a radiologist at the Kasr Eleini Teaching Hospital at Cairo University, said there was no evidence of a skull fracture caused by a blow to the head - a suggestion made after x-rays taken in 1968 - but the broken leg may have been serious enough to kill the pharaoh.
"There was no evidence of violent trauma to the skull or chest. But there is a possible fracture to the femur that may have led to his death," Dr Selim said.
Whatever caused the fractured thigh bone is likely to have also caused an open wound that was serious enough to cause an infection, fever and death. One explanation could be a hunting accident.
The tomb of Tutankhamun was discovered in 1922 by the British archaeologist Howard Carter. It soon emerged that the mummy was of a high-ranking royal who had died suddenly and had been buried in some haste - his tomb was probably meant for someone else.
The tomb was set in the Valley of the Kings near Luxor and was filled with 5000 artefacts, including a gold face mask.
The mystery of Tutankhamun's death deepened after the mummy was x-rayed in 1968 by scientists at Liverpool University, who suspected foul play because they had detected bone fragments in the skull, suggesting a violent blow to the head.
The latest CT scan is far more sophisticated and involved taking 1900 digital images of cross-sections of the body.
"We found the mummy was in a critical stage of preservation. The body was cut into several parts with some missing pieces," Dr Selim said.
It is likely the body was badly damaged during the mummification process or during its excavation and removal from the tomb in 1922 - a scenario favoured by Dr Selim and his colleagues.
In the cranial cavity they found loose bone fragments that were not covered by the solidified embalming material. The fragments exactly matched a defect in the first vertebra of the neck.
"We believe that this broken piece from the first vertebra of the king's spine may have been fractured and dislodged when Carter and his team tried to remove and free the gold mask," he said. "It was tightly glued and quite adherent to the body."
Who was Tutankhamun?
The boy king ascended to the throne when he was just 8 years old and lived during a turbulent period in the history of ancient Egypt before he died in 1352BC.
Some scholars have suggested he may have been murdered by his prime minister, Ay, because the boy king was seeking greater independence.
Others suggest he was killed by a high priest called Panahesy who accused him of blasphemy.