A record haul of rare antiquities illegally looted from Italy and discovered during raids on the Swiss warehouses of an accused Sicilian art dealer was unveiled by authorities on Wednesday.

Police estimated the value of the 5,361 vases, bronze statues and frescoes at about €50m (£38m).

The works, dating from the eighth century BC to the third century, were laid out at the Terme di Diocleziano National Roman Museum and may go on public display before being returned to museums in southern Italy.

“This is by a long shot the biggest recovery in history in terms of the quantity and quality of the archaeological treasures,” the Carabineri general Mariano Mossa said.

The items were found during an investigation into Basel-based art dealer Gianfranco Becchina and his wife, Ursula Juraschek, also known as Rosie, who were accused by prosecutors of being part of an antiquities trafficking network that involved “tombaroli” tomb raiders in southern Italy, dealers and buyers around the globe.

Becchina remained free because the charges against him had expired, police said.

The investigation showed how dealers would forge provenance papers for the antiquities and create fictitious histories for them, so that museums and private collectors could in theory buy them in good faith, police said.

Police said that as a result, Italian authorities now had detailed documentation of Becchina’s inventory, including photos and receipts, that were also found in the warehouses.

David Gill, professor of archaeological heritage at University Campus Suffolk and author of the Lootingmatters blog, said the documentation will likely point to objects that were now in top museums and would certainly be on the Italians’ list for repatriation.

For over a decade, Italy has been on a campaign to reclaim treasures that were looted from its soil and sold to top museums and private collectors.