King Tutankhamen, Egypt's best-known pharaoh, was a frail youth who died due to "severe malaria" more than 3,000 years ago, researchers have said, following extensive DNA analysis on his remains.
Scientists from Egypt, Germany and elsewhere, have been conducting DNA tests and CT scans on King Tut's mummy for the past two years, uncovering new details of the young ruler's lineage.
In a study to be published in the Journal of the American Medical Association on Wednesday, the scientists say the boy king was born with a cleft palate and clubfoot, and his parents were most likely brother and sister.
"This is how King Tut died, from severe malaria," Zahi Hawass, Egypt's senior archaeologist and co-author of the new study, said on Tuesday.
"We actually can say for the first time that we revealed the mystery behind the family of the Golden Boy - King Tut.
"He had severe necrosis and deformities in the toe of his left foot, and it caused him severe pain. This is why he was limping, he couldn't walk normally.
"130 canes were discovered in his tomb when it was unearthed," he said.
Mystery has surrounded King Tut since his tomb was discovered intact in 1922, yielding a stunning array of treasures, including a golden funeral mask.
He is believed to have ascended the throne at around 10 years of age, but died before his 20th birthday, sometime around 1324 BC.
Theories of the cause of his death have ranged from supernatural forces, poisoning by his sister, to genetic diseases.
A hole in King Tut's skull was thought to be connected to his death, but a 2005 CT scan found it was likely created by the mummification process.
The latest findings indicate the young pharaoh had a weak immune system due to genetic disorders, probably brought about by inbreeding among ancient Egypt's royals. His death came from complications from a broken leg, along with malaria infection.
The new study also offers new details on King Tut's lineage, based on tests performed on 15 other royal mummies. It is thought that Tutankhamen's father was the pharaoh Akhenaton, who ruled Egypt for 17 years alongside Queen Nefertiti.
"I really believe that the reason for the deformities and the weakness in the bones came because Akhenaton, his father, married his full sister," Hawass said.
The identity of Tut's biological mother has yet to been confirmed, though.