The suspects from northern Germany were arrested months after a Nov. 22, 2022 break-in at the Celtic and Roman Museum in the Bavarian town of Manching, in which 483 Celtic coins discovered during an 1999 archaeological dig were stolen. The coins dated to around 100 B.C.
The coins and a lump of unworked gold were originally discovered during excavations of an ancient settlement in Manching, and authorities have said they are considered the biggest trove of Celtic gold found in the 20th century.
Most of the stolen treasure is still missing, but investigators found lumps of gold on one of the suspects when he was arrested that appear to have resulted from part of the treasure being melted down.
Investigators have said that cables were cut at a telecommunications hub, knocking out local networks, before the heist, and that the thieves got in and out of the museum in nine minutes during the night without triggering an alarm.
The four defendants were accused of a total of 20 break-ins or attempted robberies in Germany and neighboring Austria, starting in 2014. Other cases involved safes or cash machines being broken into.
The defendants didn't address the charges during the roughly six-month trial, but their lawyers called for their acquittal.
The court sentenced them to prison terms ranging from four years and nine months to 11 years.