Michael Seifert, a former Nazi SS prison guard known as 'the beast of Bolzano' for his cruelty, has died in an Italian hospital aged 86.
He was serving a life sentence in prison in southern Italy, and died in hospital in Caserta where he was admitted several days ago.
Seifert was convicted in absentia in 2000 by an Italian military tribunal of 11 murders at a prison camp in Bolzano.
He was extradited to Italy from Canada in 2008.
Seifert admitted to having been a guard at the camp but denied being involved in atrocities.
Witnesses accused him of leaving a prisoner to starve to death, raping and killing a pregnant woman and gouging an inmate's eyes out.
Towards the end of World War II, the Bolzano camp in Italy's Alpine South Tyrol region was used to house Jews, resistance fighters and German army deserters who were being transported further north.
Seifert was born in Ukraine and went on to work as a Nazi guard after the German occupation. After the war, he concealed his past and entered Canada in 1951.
In 2002, he was arrested after a request from Italy. His attempts to resist extradition reached a dead end in Canada's Supreme Court when it refused to hear his appeal.
Seifert had been transferred to hospital from the nearby Santa Maria Capua Vetere prison. He had a fractured femur and underwent an emergency operation for a gastric complication days ago, Pasquale La Cerra, the medical director at the Caserta hospital, told AP news agency.