Italian and German police arrested 10 suspects overnight who are accused of associating with the 'Ndrangheta and 'exporting' clans from the Calabria-based mafia organisation.
The 'Rheinbruecke' operation followed the recent 'Helvetia' operation that uncovered the export of 'Ndrangheta clans to Switzerland which reported directly to the mafia's Calabrian leadership, police said.
Junior defence minister Gioacchino Alfano praised Italian and German police for Tuesday's "brilliant" operation.
The 'Ndrangheta, Italy's wealthiest mafia, emerged in the mid-1970s and runs a drugs and extortion business worth billions of euros.
It has links to Columbian drugs cartels and is one of the world's most powerful criminal groups.
The organisation operates mainly in Italy and Europe but extends its influence and networks from Italy across the world.
A report by Italy's anti-mafia directorate in 2011 described the 'Ndrangheta as having "virtually unlimited resources".
