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 for the local prosecutor's office said yesterday.
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.
Mr Zuroff said: "We were informed the case is being taken seriously and can only hope it will be expedited in an appropriate manner."
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.
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.