Ukrainian-born John Demjanjuk was sentenced by a Munich court in May 2011 after an 18-month trial [AFP]

Former Nazi death camp guard John Demjanjuk, sentenced to five years in a German prison last year in one of the last major trials of its kind, has died at the age of 91, police have said.

The Ukrainian-born Demjanjuk had been found guilty of more than 27,000 counts of accessory to murder during the six months he was a guard at the Sobibor death camp in 1943.

The ailing Demjanjuk was sentenced by a Munich court in May 2011 after a trial lasting 18 months.

He was allowed to go free pending an appeal, however, having already spent nearly two years in prison on the grounds that he was not a threat and was unlikely to abscond, being stateless.

Police in the southern state of Bavaria said he died in an old age home in the town of Bad Feilnbach, adding that prosecutors would now conduct a routine investigation into the cause of death.

While there was no direct evidence of his presence or actions at Sobibor in German-occupied Poland, the German court said it was convinced he had been a guard, and was thus automatically implicated in killings carried out there at
the time, mainly of Dutch Jews.

He had denied the charges and appealed against his conviction.

Death sentence

Demjanjuk went to live in the United States after the war but in 1986, he stood trial in Jerusalem accused of being "Ivan the Terrible", an infamous Ukrainian guard at another death camp, Treblinka.

Found guilty of all charges and sentenced to death in 1988, he was freed five years later when evidence surfaced proving Israel had got the wrong man.

After evidence emerged that he served as a guard at other Nazi camps, he was stripped of his US citizenship in 2002 for lying about his war record on immigration forms.

Years of legal wrangling ensued and he was deported from the United States to Germany in 2009 to face trial anew.

Because of ill health, Demjanjuk attended much of his trial in Germany either in a wheelchair or lying on a hospital bed, wearing dark glasses and a baseball cap. He rarely spoke during the proceedings.