John Demjanjuk, who was found guilty for his role as a guard at a Nazi death camp in World War II, has died aged 91, say reports from Germany.
He had been sentenced in May 2011 by a German court to five years in prison, but was released pending an appeal.
Media reports say he died at a retreat.
The court said Demjanjuk, 91, was a guard at Sobibor camp in Nazi-occupied Poland in 1943. He denied this, saying he was a prisoner of war and a victim too.
An estimated 250,000 people died in the gas chambers at Sobibor. Demjanjuk was convicted of being an accessory to the murder of the 28,060 people who were killed there while he was a guard.
Demjanjuk's family said during his trial that he was very ill.