Polish authorities have reopened an investigation into crimes committed at Auschwitz and satellite camps during World War II.
It is estimated that a million people - mostly Jews and non-Jewish Poles - were killed at the Nazi death camp.
The new investigation is being carried out by the Institute of National Remembrance, a state body that investigates Nazi and communist-era crimes, the BBC reports.
The investigation, one aim of which is to track down any Nazi war criminals still living, was opened by the institute's branch at Krakow, near Auschwitz.
"We do not discount the possibility of finding alive former employees of the Auschwitz-Birkenau concentration camp," says Piotr Piatek of the institute, "in which case they may be accused of crimes against the Polish nation."
It was not immediately clear if investigations into other death camps operated across German-occupied Poland - such as Treblinka, Sobibor, Chelmno and Belzec - were also planned.
Poland originally launched investigations in the 1960s and 1970s into crimes at Auschwitz, but closed them in the 1980s without any indictments made.
During the communist era, Poland had difficulty questioning witnesses and perpetrators living abroad because the country was part of the Soviet bloc.
Leading international Nazi hunter Efraim Zuroff has praised the reopening, saying it could have "tremendous implications" in paving the way for new prosecutions.