WARSAW, POLAND -- Polish prosecutors are investigating an apparent mass burial site revealed this month near the area of the former Nazi German death camp of Auschwitz.

A local resident spotted some 12 human skulls and many bones in the bank of the Sola river, running through the Polish southern town of Oswiecim, when the water level was very low, the Onet portal said Friday.

Police and prosecutors are investigating whether the remains might have a link to the former death camp and the state National Remembrance Institute, which investigates World War II and communist-era crimes, has been notified.

The press office of the Auschwitz Museum said Friday it was aware of the find, and of others before it, but that the area is outside the museum's perimeter and administrative authority.

Any further steps depend on the findings from the investigation.

During World War II, from 1940-45, over 1.1 million people were killed at Auschwitz, which Nazi Germany operated in Oswiecim, in occupied Poland. Most of the victims were Europe's Jews but also Poles, Gypsies, Russian soldiers and German political prisoners. Most -- but not all -- bodies were incinerated in the camp's crematoria.