(CNN) — Forget overtime. This construction crew hit the mother lode. Eight construction workers uncovered gold coins and bars worth 9 million euros ($10.5 million) in Belgium last Tuesday while at work, according to authorities. They made the golden discovery underneath a building they were performing renovation work on in the city of Dendermonde, about 19 miles northwest of Brussels. The extraordinary haul of approximately 40 gold bars and 4,000 gold sovereign coins was found hidden in the foundations of an old brewery, Patrick Feys, chief of the Dendermonde Police District, told CNN. Kobe Phillips, a student working a part-time construction job, made the discovery. “I thought they were one-euro coins, neatly lined up in a row. We dug them out, and then we saw a small bar of gold lying there, already attached to our digging hammer. There was actually a bit more than we’d thought,” Phillips told Belgium broadcaster VTM. Once the discovery was made, the workers contacted the property owner who then called the police, Feys told VTM. The East Flanders Public Prosecutor’s Office told CNN that police were called because of the large value involved and that the gold is now being held in a “secure and guarded location.” Images on the Dendermonde police’s Facebook page show a metal bucket filled with gold coins and a table covered in gold bars. Feys told CNN that some of the gold bars bear stamps dating to the 1960s, while the sovereign coins feature different monarchs and dates. The discovery has already prompted potential claimants to emerge. “We already had some citizens who want to claim the gold with different documents to prove that they are descendants,” Feys said. A police investigation is underway to determine whether there are any criminal aspects to the case. ...read more read less