The study builds on research by Frank Rühli of the Institute of Anatomy at the University of Zurich in Switzerland, published in June this year, which showed that the 46-year-old iceman bled to death when an arrow lacerated the subclavian artery, which lies just below the collarbone.
Rühli had conducted CT scan on the body and found a lesion very close to the shoulder artery.
A previous scan on the body in 2005 by Dr. Rühli, Dr. Eduard Egarter Vigl of the South Tyrol Museum of Archaeology in Bolzano, Italy, and Drs. Patrizia Pernter and Paul Gostner from the Department of Radiology at General Hospital Bolzano had revealed a lesion of the dorsal wall of the left subclavian artery.
The artery is underneath the clavicle, which was caused by a previously undetected arrowhead that remains in the back of the ice mummy - first discovered in 1991 in the melting glacier 10,500 feet (3,210 meters) above sea level in the Ötztal Alps in South Tyrol, northern Italy some 15 years ago - hence the name Oetzi.
Albert Zink, director of the Institute for Mummies and the Iceman at the European Academy in Bolzano, Italy said the only "new thing researchers have now detected is the trauma of the skull".
"The wound from the arrowhead was so severe that he would have died from it alone. But it was probably a combination of these two injuries," said Zink.
Rühli, however, said the head trauma, probably caused by a blow to the head, was secondary to the fatal arrowhead wound. "If the artery starts bleeding, it's a matter of minutes to die, [while] the trauma to the head is maybe a major trauma ... but it doesn't kill you instantly," said Rühli.
Zink said scientists are, however, still unsure whether the head trauma or the arrow wound came first, adding that arrowhead and head trauma evidence has still failed to reveal the sequence of events that led to Oetzi's end.
Zink said the most probable scenario was that Oetzi was first struck by the arrow and then struck in the head, or that he hit his head on rocks when he fell.
The findings appear in the current issue of the archaeological magazine Germania, reports National Geographic.