The frozen remains of a man who died in the Alps more than 5,000 years ago have left Vienna for the Italian city of Bolzano, where they will be put on display for the first time to the public. Heavy security measures are being taken by Austrian and Italian police for the journey after threats by a Tyrolean separatist organisation to prevent the naturally mummified body, discovered in 1991, from leaving Austria. Our Rome correspondent, David Willey, reports:

Both countries are taking seriously threats of terrorist action by the United Tyrol Movement to prevent the transfer from Vienna to Bolzano. Police helicopters will monitor the ice man's journey to his final resting place in an armoured van.

Ownership of this unique archaeological specimen, a stone age hunter who died in a snowstorm in the Alps thousands of years ago and whose body and possessions were preserved almost intact by a freak of nature, has been hotly disputed between Italy and Austria. The body was found in what was eventually agreed was Italian territory, only a few metres away from the Austrian frontier.

After seven years of tests and analyses carried out by an international team of experts in Austria, the ice man will be placed inside a special refrigerated container at a new museum in Bolzano, the capital of the South Tyrol, which was ceded by Austria to Italy at the end of the First World War.

Visitors will be able to look through a glass window into the refrigerator, where the body will be kept at six degrees below freezing and at almost 100% humidity - the same conditions which preserved it for so many centuries.