Last Wednesday morning, 40 houses across the Italian regions of Sicily, Calabria, Piedmont, and Apulia, as well as Germany, the U.K., and Spain were raided as a four-year-long police sting to capture a criminal gang responsible for stealing $47m of archeological goods came to a head.

The Italian crime ring, which has been described as “very well organized” by the Europol, has been at large for several decades. Code-named Demetra, the operation involved more than 250 officers, who detained 23 suspects as a part of a crackdown of an international group responsible for the illegal excavation and trafficking of cultural goods.

The revelation could have an enormous impact on scholarly studies. One report noted that the gang set up workshops where teams of counterfeiters copied some of the archaeological remains and sold replicas as originals. Elizabeth Marlowe, professor of art history at Colgate University, said this might be the first documented evidence we have that forgeries and original artifacts travel in the same network. Marlowe commented that some dealers are more inclined to purchase looted goods because at least their confident of authenticity. However, if they get caught with forgeries, it “undermines their prestige, special knowledge, and connections with the ancient world.” But if criminal gangs are selling replicas, then it directly contradicts this train of thought. “It’s the same traffic pattern at the same time,” she said. “It could have a convulsive impact.”

Marlowe said it all depends if police recover any form of archive from the gang. If there’s an archive of whose hands this has passed through, everyone in the field, museums, auction houses, art collectors, curators, can see if they’ve been impacted. “Forgeries are completely toxic, they end up in prestigious collections and become the bench markers for how we understand the ancient norm.” According to British newspaper the Telegraph, police told reporters the loot had been “cleaned up with fake attribution of origin and put on the legitimate art market through the auction houses in Munich.”

Caltanissetta, in the center of Sicily where the goods were stolen from, is renowned for its rich archaeological sites from the Greek and Roman epochs. The Valley of the Temples, a UNESCO world heritage site and one of the main locations the gang pilfered from, is famed for its pagan and Christian necropolises and the crawling network of subterranean aqueducts.

Backed by technical and support teams in London and Barcelona, the huge operation involved smuggling goods out of Italy through false provenances and appeared at auction houses in Munich under the guise they were being sold as part of a private collection. Marlowe explained that if the forged documents had been recovered alongside the artifacts it might give the police and academic communities a better insight into how they’re made.

The proceeds ended up in London and then Barcelona, traveling back to Italy via Spain—couriered by eight men aged between 39 and 71, making sure not to exceed the transportable cash limit. Alongside the 20 Italians who have been arrested, Thomas William Veres, a British art dealer, has also been detained.

According to local news site Giornale Di Sicilia, on one occasion, a courier had hidden some Greek-era silver coins in his wallet to divert the controls at the airport. The Italian news site also described how the investigation was first set in motion: “The investigation started with an anti-Mafia investigation by the Nissena Prosecutor on the territory of Riesi and took international developments when the Carabinieri set out on the trail of Gaetano Patermo , 63, of Riesi, who had contacts not only with the couriers that sold finds in the north but also with members of another organization that operated between London, Barcelona and Munich.”