For the alleged crime of stealing sand, a French couple could face as much as six years behind bars.
The pair was stopped by police as they were about to board a ferry home to France. In the trunk of their car were 14 bottles of white sand from a beach in southern Sardinia, about 90 pounds' worth, the BBC reported.
The man and woman said they took the pristine sand as a souvenir and did not know it was illegal to remove sand or shells from the famed Italian island.
In the past 10 years, airport authorities have seized 10 tons of sand pilfered by tourists, according to The Local, endangering the coastline, which already faces erosion problems.
Some tourists have even auctioned bottles of Sardinia sand online, environmentalists said.
"Sandy beaches are of the main attractions of Sardinia," said Pierluigi Cocco, an environmental scientist who lives in the Sardinian capital of Cagliari, the BBC reported.
"There are two threats;" one is due to erosion, which is partly natural and partly induced by the increasing sea level due to climate change; the second is sand stealing by tourists," he said.