A Frenchman was caught trying to leave the Italian island of Sardinia with 41 kilogrammes (90 lbs) of pebbles and stones, accused of illegally taking them from a beach, authorities said Tuesday.

He risks a fine of up to 3,000 euros ($3,235) after being found with the haul while trying to board a ferry from Porto Torres to the French port of Nice, the customs agency said.

"Checks revealed that in the boot of his car he had 41kg of pebbles and stones taken from the Lampianu beach," which have now been seized and will be relocated, the agency said.

Sardinia is known for its pristine white sand beaches -- sand so prized that regional authorities passed a law in 2017 to prevent tourists taking it home with them.

Taking, holding or selling sand, pebbles, stones or shells from Sardinia's coast or sea without permission is punishable by a fine between 500 and 3,000 euros.