CNN  — 

Police in Poland have launched an investigation after a collection of more than 100 Bronze Age artifacts surfaced unexpectedly in the northwest of the country.

The discovery came to light when photos of the artifacts, including weapons, bronze spearheads, necklaces and shield bosses, were shared with the Provincial Heritage Protection Office in the city of Szczecin, according to a statement from the West Pomeranian Police, published Friday.

Courtesy of Polish Police
Necklaces and weapons were among the artifacts.

When a specialist art-theft investigator tracked down the people who had shared the photos, they said the artifacts had been left anonymously outside a local historical association in the town of Gryfino.

The historical association then handed the artifacts over to the Provincial Heritage Protection Office in Szczecin, which reported a crime of finding treasure without permission.

Courtesy of Polish Police
Police said those responsible for illegally excavating the artifacts could face up to eight years in prison.

“The treasure was acquired through illegal searches and was then excavated, which caused it to completely lose its archaeological context,” the police said, adding that this makes radiocarbon dating impossible.

“This is one of the largest treasures found in Poland in recent years,” they said.

Those responsible face up to eight years in prison, according to the statement.

The artifacts have been transferred to the Provincial Heritage Conservator’s office in Szczecin, which will decide where the items will ultimately be housed.

CNN has contacted the police for comment.