Twenty people have been arrested in recent days in a police operation spanning 10 countries.
The operation was coordinated by Europol and Eurojust, with the aim of dismantling a criminal organization whose members were involved in trafficking large quantities of cocaine in Europe.
The ethnic Albanian gang called Kompania Bello imported cocaine from Latin America to Europe.
The investigations were launched in May 2015 by the Italian authorities and extended to Germany, Spain, Hungary, Greece, the Netherlands, the UK, Romania, Albania and the United Arab Emirates.
Two suspects were arrested in Attica on Tuesday, both ethnic Albanians.
A 40-year-old Albanian national based in Ecuador is described as the ringleader.
The gang maintained contacts with members of Latin American cartels and transported large quantities of cocaine to major European ports.
The members of the organization then transported the drugs to various EU countries hidden in trucks with legal cargo.
During the five-year investigation, a total of 84 members of the organization have been arrested, and more than 3.8 tons of cocaine and over 5.5 million euros were seized by authorities.