The Egyptian experts, who consulted with counterparts in Italy and Switzerland, "have found that a fracture in the boy king's left leg a day before his death was infected with gangrene and led to his passing," Egypt's Supreme Council of Antiquities stated.
The revelation followed introduction of the first facial reconstruction of Pharaoh Tutankhamen, a 5-foot-6, 19-year-old that looks similar to his portraits, Australia's Special Broadcasting Services reported.
Independent teams of artists and scholars from Egypt, France and the United States worked on reconstructing Tut's face, the New York Times reported.
Egyptians gave their famous pharaoh a strong chin while the American and French teams produced a weak chin, the newspaper said.
British archeologist Howard Carter had speculated the boy king was killed by a blow to the head when he discovered the sarcophagus in 1922.