The mafia members were arrested in a sweep that uncovered dealings in flowers and chocolates as well as drugs and arms, Italian anti-mafia prosecutor Franco Roberti said.
The mafia centred in southern Calabria have "great flexibility, adapting to markets that offer the most opportunity to get rich," Rome deputy prosecutor Michele Prestipino told a news conference on Monday.
"This operation has shown that the 'Ndrangheta families today have the financial and human means to colonize outside their home territory," Prestipino said.
The probe uncovered trafficking in 260 tonnes of Lindt chocolate worth more than €7 million stolen in Italy late last year and sold on in Italy, Poland, Austria and Switzerland, the prosecutors said.
In what was described as the biggest robbery of its type, thieves in Italy have stolen a staggering 260 tons of chocolate from Swiss company Lindt & Sprüngli in 2014.
The Zurich-based company initially confirmed the losses following an announcement by Italian police about the recovery of 50 tons of chocolate in Nola, near Naples.
The stolen chocolate — 5,000 boxes of the Lindor brand —was valued at €1.5 million, police said.
But it was just a portion of the booty stolen from an external warehouse in Milan in August, a Lindt & Sprüngli spokeswoman told the Tages Anzeiger newspaper.
The value of the stolen sweets is close to €8 million, Italian news agency Ansa reported.
The 'Ndrangheta are the most active, richest and most powerful organised crime syndicate in Europe, according to Italian authorities.