A former Nazi concentration camp guard living in the Berlin area is being investigated on suspicion of murder after authorities received a tip from the Simon Wiesenthal Centre, prosecutors say.
The 87-year-old, identified only as Horst P, is alleged to have been involved in killings while serving as a guard at the Dachau camp near Munich, a spokesman said.
The Wiesenthal Centre's top Nazi hunter Efraim Zuroff said information on the suspect came in after the organisation launched a poster campaign in Germany in July seeking tips on the whereabouts of former guards and Nazis. He passed it on to Berlin prosecutors after confirming the suspect really had been a Dachau guard.
"We were informed that the case is being taken seriously, and we can only hope it will be expedited in an appropriate manner," Mr Zuroff said in a telephone interview from Jerusalem.
Germany's Bild newspaper first reported the case, publishing an interview with the suspect in which he is quoted as denying involvement in any killings.
But, he acknowledged, "when one of the criminals caused a disturbance I reported him, then he was picked up and taken to a special camp. Sometimes I never saw them again but I also never asked any questions."
German authorities are investigating about 30 former Auschwitz guards under new legal thinking that anyone who served in a death camp, whose sole purpose was to kill, can be prosecuted as accessories to murder.
That argument has not been successfully expanded to include guards at concentration camps like Dachau, where tens of thousands died but whose purpose was not solely killing.
In this case, that means that prosecutors will have to find sufficient evidence of a specific crime before they can file charges.
In Bild's story, the newspaper printed a photo collage they said was on the wall of the man's apartment. It was labelled Mein Kampf - the same title as Adolf Hitler's notorious book - and included photos showing him in uniform.
He was also quoted as saying he joined the SS because he "was told that it was fun".