Berlin (AFP) - German prosecutors said Friday they had opened preliminary investigations against three Nazi-era Auschwitz concentration camp guards suspected of complicity in murder.

"There are three possible suspects who were guards" at the extermination camp located in what was Nazi-occupied Poland, a spokesman for the prosecutors office in the northern city of Hanover told AFP.

The three men are all aged around 90, said regional newspaper Neue Osnabruecker Zeitung.

About 1.1 million Jews, Roma and Sinti, homosexuals and others died in gas chambers or of forced labour, sickness and starvation at the Auschwitz-Birkenau camp from 1940 until it was liberated by the Soviet Red Army in January 1945.

The three men are on a list of 30 suspects compiled by the German office investigating Nazi war crimes that was passed on in September to regional prosecutors with recommendations to bring charges.

The office in the southwestern city of Ludwigsburg, which cannot itself launch prosecutions, had initially examined 49 files of former Auschwitz guards, the oldest aged 97.

Of these, nine have since died, seven live abroad and two have not been found. One man, identified by media as Hans Lipschis, is already the subject of proceedings by prosecutors in the southwestern city of Stuttgart.

For more than 60 years German courts only prosecuted Nazi war criminals if evidence showed they had personally committed atrocities, but since a 2011 landmark case all former camp guards can be tried.

In that year, a Munich court sentenced John Demjanjuk to five years in prison for complicity in the extermination of more than 28,000 Jews at the Sobibor camp, where he had served as a guard.

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