Italian police said on Wednesday they had seized about 14 tonnes of amphetamine pills worth around 1 billion euros ($1 billion) arriving from Syria, in what they described as the world's single largest operation of its kind.
Investigators said they impounded three container ships that had docked in the southern Italian port of Salerno and found 84 million pills of the drug Captagon inside machinery and large paper cylinders for industrial use they were carrying.
"It is possible that the local Camorra crime groups are involved in this business," Lieutenant Colonel Giordano Natale told Reuters.
Used in the 1960s to treat narcolepsy and depression, Captagon is one of several brand names for fenethylline hydrochloride, a drug compound belonging to a family of amphetamines that can inhibit fear and ward off tiredness.
Captagon is popular in the Middle East, and widespread in war-torn areas such as Syria, where conflict has fuelled demand and created opportunities for producers.
Production was initially concentrated in Lebanon and the Islamic State group sells it to finance its activities, police said in a statement.
It said Captagon was known as the "drug of the Jihad" after being found in militant hideouts, including one used by the Islamists who killed 90 people at the Bataclan theatre in Paris in 2015.
Italian authorities believe the coronavirus lockdown cross Europe has hindered the production and distribution of synthetic drugs, forcing traffickers to organise shipments from Syria, where these activities have not slowed down.
In a raid two weeks ago, Italian police seized 2,800 kg of hashish and 1 million Captagon pills in the port of Salerno. The shipment was hidden among counterfeit clothing items.