The man, named only as Samuel K., is suspected of having been a guard at the camp between in 1942 and 1943 and of personally shooting dead several Jews, prosecutors in the western German city of Dortmund said.
He admitted being a guard at Belzec in German-occupied Poland in World War II but he denied being personally involved in killing people, according to the statement. No incriminating material was recovered in the raid.
Since the Nuremberg Trials after the war, where several top Nazi henchmen were sentenced to death, German authorities have examined more than 25,000 cases but the vast majority never came to court.
However, as the suspected war criminals approach their nineties, there has been a flurry of arrests and court cases dealing with war-time atrocities, in what Nazi-hunters say is a welcome change of policy in Berlin.
In the most high-profile case, 89-year-old John Demjanjuk went on trial in Munich on November 30 on charges of assisting in the murder of 27,900 people while a guard at the Sobibor death camp. He denies the charges.
Der Spiegel magazine reported in November that Samuel K. was due to appear as a witness in Demjanjuk's trial and has admitted several times working as a guard at Belzec.
"It was clear to us all that Jews were killed there and were later burned too. We could smell it every day," the magazine cited him as saying.