Police from Italy, Britain, France, Germany and Serbia arrested 23 suspects and carried out 103 searches in the investigation that started in 2017, the EU police agency Europol and Eurojust said.

Two suspects were arrested and 21 more were placed under house arrest, said Bartolo Taglietti, who leads Italy’s Command for the Protection of Cultural Heritage in Calabria, where most of the arrests were made.

Several suspects were detained in Milan and other Italian cities.

Taglietti added that many of the 10,000 stolen artefacts had already been sold off, some in prestigious auction houses in London, Munich, Dijon and other European cities.

Italian law dictates that all artefacts found within the country’s borders belong to the state.

Some of the stolen objects are said to date as far back as the fourth and third centuries BC and include five terracotta vases and oil lamps, plates depicting animal scenes, brooches and various jewels, according to local media.

The gang used bulldozers to dig craters, before sifting through the earth and passing it through metal detectors, the reports added, quoting police sources.

Using a drone, police were able to catch the looters red-handed as they dug around sites in Calabria.

Although they attempted to disguise themselves by wearing ski masks, the drone was able to pick up the license plate numbers of their vehicles.

According to the most recent stolen artworks bulletin issued by Italy’s Carabinieri, 8405 items have gone missing in Italy in the last year.