King Tut probably died from a broken leg, scientists say, possibly closing one of history's most famous cold cases.

A CT scan of King Tutankhamun's mummy has disproved a popular theory that the Egyptian pharaoh was murdered by a blow to the head more than 3,300 years ago.

Instead the most likely explanation for the boy king's death at 19 is a thigh fracture that became infected and ultimately fatal, according to an international team of scientists.

The team presented its results this week at the annual meeting of the Radiological Society of North America in Chicago, Illinois.

"I think it is the end of the investigation. … We can now close this file," said team leader Ashraf Selim, a radiologist at Kasr Eleini Teaching Hospital at Cairo University in Egypt.

But the research effort may add to rumors surrounding the infamous "curse of Tut."

During their investigation, the scientists experienced several mysterious occurrences, from a freak sandstorm to a strange power outage.

"People love to say it's the curse [whenever strange things happen around King Tut]," Selim said, chuckling.

"Of course, being a scientific man, I don't believe in these things."

No Skull Fractures

Tutankhamun, who ascended to the throne at the age of eight, was mummified and buried with other ancient royals.

His tomb, filled with 5,000 artifacts, was discovered near Luxor, Egypt, in 1922 by a team of archaeologists led by Howard Carter.

Tut had been affixed to his coffin by resins used in the embalming process.

Carter and his colleagues dismembered much of the mummy while removing the body from its sarcophagus. The damage they did is in some cases difficult to distinguish from the damage dating back to the king's lifetime or the embalming process.

During an x-ray of the mummy in 1968, scientists found bone fragments in Tut's skull, prompting a sensational theory that the boy king had been bludgeoned to death by his political enemies during a particularly volatile time in Egyptian history.

(See a National Geographic magazine feature on King Tut's life and death.)

The latest scan, however, showed no skull fractures. It did show that the two bone fragments in Tut's cranial cavity exactly matched some missing pieces from the pharaoh's first vertebra, near the skull.

Because the fragments were loose and not covered with solidified embalming material, the damage must have occurred after the pharaoh's remains were prepared for burial, scientists concluded.

Selim believes the bone fragments may have been dislodged when Carter's team tried to remove Tut's gold mask, which was tightly glued to the body.

"The damage probably occurred because of the bad handling of the mummy," Selim said.

"If these pieces of bone [were dislodged] before death, we would assume they would be stuck to the resin inside the skull, not just loose there."

Severe Infection

The scientists set up a mobile, noninvasive CT scanner in Luxor to perform a full-body scan on the king's remains, obtaining about 1,900 digital cross-sectional images.

Selim says Tut's remains are "in a terrible shape," with most of the bones having been broken after the mummy was discovered.

The scientists have focused on a fracture in Tut's left thigh bone as the most likely cause of death.

The CT scan showed a thin coating of embalming resin around the leg break, suggesting that Tut broke his leg just before he died and that his death may have resulted from an infection or other complications.

"The resin flowed through the wound and got into direct contact with the fracture and became solidified, something we didn't see in any other area," said Selim.

"We could not find any signs of healing of the bone."

There were no antibiotics 3,000 years ago, so the probability of a severe infection resulting from such a break would be quite high, according to Selim.

"It's probably what killed him," he said.

John Benson, who is the chief of radiology at Mount Desert Island Hospital in Bar Harbor, Maine, has used similar medical imaging to determine what killed a group of French settlers who arrived on Saint Croix Island in Maine in 1604.

He agrees that the leg break likely led to Tut's death.

"But there's always going to be speculation," he said.

"There is a number of possible causes of death for which there would be no residual evidence. Tut could have had pneumonia, or he could have died from a communicable disease.