In a major blow to Italy’s most powerful mafia, police yesterday said they had arrested more than 300 suspected members of the ‘Ndrangheta syndicate, including its top boss, 80-year-old Domenico Oppedisano.

A press conference was held in Milan where Mario Parente, head of Carabinieri ROS (Raggruppamento Operativo Speciale (special operation department) addressed those present including Italy’s top anti-Mafia prosecutor Piero Grasso and Italian prosecutor Ilda Boccassini, among members of the press and other top officials.

About 3,000 police officers made arrests and seized tens of millions of euros in assets in the southern region of Calabria and across northern Italy, in the largest operation against the ‘Ndrangheta in the last 15 years.

Mr Oppedisano, who was more of a top representative of local clans than an overlord, was elected at the top of the ‘Ndrangheta in August 2009 during a wedding, according to Italian media.

The operation "struck the ‘Ndrangheta at the heart of its criminal system, both in terms of organisation and in terms of finance," Interior Minister Roberto Maroni said.

Police seized assets, weapons and drugs and arrested entrepreneurs working in the health sector and a local healthcare manager in northern Italy. Suspects were arrested on suspicion of mafia association, murder, arms offences, trafficking, extortion and other crimes.

The arrests in northern Italy, aimed at the ‘Ndrangheta’s commercial interests, "confirm that northern Italy is the true theatre of operations for the ‘Ndrangheta," anti-mafia prosecutor Alberto Cisterna said.

Healthcare "is the sector they prefer, since it allows them to establish contacts with politics and with public administration," Mr Cisterna said.

The operation shows how the ‘Ndrangheta is organised in a vertical structure, in some ways resembling that of Cosa Nostra, the Sicilian mafia, and not a horizontal one as earlier suspected.

"The ‘Ndrangheta still has its head in the heart of Calabria," Antonio Nicaso, a ‘Ndrangheta expert and professor of the history of organised crime at Middlebury College in the US state of Vermont said.

Mr Nicaso believes this operation to be "the mother of all investigations," because besides showing how the syndicate is organised, it also discovered the secrets of the ‘Ndrangheta "summits, initiation rites and elections."