Greek police seized 70 tonnes of smuggled tobacco and 8.8 million cigarette packets at two illegal tobacco manufacturing facilities in Aspropyrgos, west of Athens.
A total of 40 people are thought to be involved in the racket.
Police believe that they imported tobacco from Italy and materials for the preparation and packaging of tobacco products from Bulgaria.
In the two factories, they used specialist equipment to produce cigarettes, put them in counterfeit packets of well-known brands, and then transported them to other storage facilities before distributing them to the market.
Police say that they even exported the cigarettes to other EU countries.
It was a sophisticated and highly profitable enterprise, according to the police.