Archaeologists discovered the remains near a field gun emplacement in one of the shelters used by Polish defenders in September 1939.

Aleksandra Trawińska, a spokesperson for the museum said that fragments of clothing suggest the remains may belong to a civilian. Investigators also found a rifle shell near the remains.

The Institute of National Remembrance (IPN) has been informed and will oversee the exhumation. Last week, archaeologists discovered three other human skeletons along with civilian clothing at a nearby location.

The remains have been sent to the Pomeranian Medical University in Szczecin, north-western Poland, for forensic analysis, which may help identify the deceased and clarify the circumstances surrounding their deaths.

Initial investigations suggest the individuals may have been victims of an execution between 1939 and 1941, during which time the Nazis operated a camp for civilian prisoners of war on Westerplatte.

Archaeological work on Westerplatte has been ongoing since 2016. In 2019, the remains of nine Polish soldiers who defended the peninsula were found, seven of whom have been identified. A memorial service for the fallen soldiers was held in 2022 at the newly built cemetery on the peninsula.

The current stage of excavation aims to locate the position of another field gun used during the battle.