Italian police on Wednesday claimed to have smashed an international Mafia drug ring that operated inside a convent in the center of Milan, without the knowledge of the nuns who live there. According to local media reports, after a three-year investigation, paramilitary Carabinieri police on Wednesday seized 30 kilograms of cocaine, arrested 33 people across northern Italy and placed another 80 under investigation. The convent's janitor, an unidentified South American with alleged links to the Colombian cartels and the 'Ndrangheta, the Mafia of Calabria region in southern Italy, was the suspected linchpin of the organization. The man was accused of arranging 'religious' journeys from South America to Italy, in which couriers posing as pilgrims hid the drug in their hand baggage. Once arrived in Milan, the cocaine was allegedly refined and cut before being redistributed in other northern cities. The police said that the nuns were completely unaware of what the convent's janitor was up to when he was arrested. In Wednesday's operation, code-named 'Hannibal,' two ' Ndrangheta drug- trafficking kingpins based in Milan were also taken into custody. They came from the small Calabrian town of San Luca, which burst onto the international crime scene in 2007 with a gangland slaying in Germany. The police said the drug runners also had a warehouse in Ghana which was allegedly set up using funds for African fisheries earmarked by the Rome-based Food and Agriculture Organization (FAO) . 