Five frescoed stone slabs stolen from a tomb in the ancient city of Paestum and trafficked by a notorious artefact smuggler went on display in Italy this week after a 10-year investigation.

Police were led to the pieces, all dating from around 400BC, after an international trafficker known as The Captain died in a road accident, leaving thousands of photographs of archaeological finds in his car.

A police squad dedicated to tracking down art and artefacts dug up illegally from Italy’s numerous ancient sites traced the slabs to the Italian-Swiss border and brought them to Rome.

The frescoes show a noble lady and her slave girls, a triumphant warrior on horseback and a young armed man walking with a donkey. Each slab has a ragged crack across the middle, having been cut in half to make smuggling easier.

Paestum, a ruined city near Naples originally founded by the ancient Greeks, boasts hundreds of unique ancient tombs. Site director Gabriel Zuchtriegel said illegal digs such as the one that yielded the five frescoes were “devastating”.

“I invite you to appreciate the beauty of this tomb, but also to reflect on this illicit business and the market that creates opportunities for it,” he added.

Italian Culture Minister Dario Franceschini, speaking at a news conference with Zuchtriegel, cited the plundering of antiquities in Syria by Islamic Statemilitants, who he said made money by illegally selling fragments.