Italian art police have searched houses and buildings in four countries, including Britain, and arrested 23 people on charges of trafficking archeological artefacts.

The Command for the Protection of Cultural Heritage, a branch of the Italian carabinieri responsible for combatting art and antiquities crimes, believe the suspects are members of an criminal gang operating in Calabria that trafficked ancient items, such as antique jars, jewellery and vases from the 4th and 2nd century BC and worth millions of euros.

Dario Franceschini, the Italian culture minister, said the operation had led to the recovery of thousands of artefacts that came from illegal archaeological digs in Calabria. The items were eventually exported to countries outside of Italy, including Germany, Britain, France and Serbia.

An investigator confirmed to the Guardian that a house inhabited by a suspected member of the trafficking ring was searched on Monday morning in the Greater London area.

Franceschini said the investigation was supported by the Metropolitan police in London, the criminal police of Baden-Württemberg and French and Serbian forces.

According to Italian police officials, the items were stolen using bulldozers that dug craters several metres deep in the areas within the provinces of Crotone and Catanzaro. The thieves then used sophisticated metal detectors to scour the area.

“The stolen finds were finally transferred abroad where they were put up for auction in important international auction houses and sold at very high figures,” said the investigators in a press conference in Crotone.

Some of the artefacts, including vases and jars from ancient Greece, were also found in the homes of the men arrested, who are all Italian.

The Command for the Protection of Cultural Heritage has been operating since 1969 to defend Italy’s cultural heritage. For 50 years, this special squad – nicknamed Monuments Men, after the George Clooney film based on an allied group of investigators given the task of finding and saving pieces of art during the second world war before the Nazis stole them – has tracked down stolen paintings and statues in a country with the highest number of art thefts in the world.

According to the most recent stolen artworks bulletin issued by the carabinieri, in the last year alone 8,405 items have gone missing in Italy. These include archaeological artefacts, ancient weapons and medieval texts. Statues and paintings have been taken from churches, which often have no security systems.

Despite the carabinieri’s record of recovering more than 3m objects of art and archaeology, over 1m pieces of art are still missing.