Officers also seized 1,300lb of drugs and a codebook with initiation rites

Italian police have arrested 163 in a major crackdown on the notorious 'Ndrangheta mafia gang- said to be the most powerful crime organisation in the country.

The crime syndicate from Calabria, in Italy's deep south, are believed to be the biggest importers cocaine in Europe. Over the last two decades, they have outgrown rival gangs in Sicilian and Naples to be regarded as the most powerful mafia organisation in Italy.

Now Italian police have dealt a major blow to the gang as they carried out arrests across the country, with more than forty alleged members and associates detained in Calabria alone.

Italian police arrest members of the notorious 'Ndrangheta mafia gang- said to be the most powerful crime organisation in the country

Officers also seized an incredible 1,300lb of drugs and found evidence of the trafficking of another 3,300lb of coke and hashish, Reuters reported.

The crackdown was coordinated by the national anti-mafia prosecutor and authorities in Bologna, who were expected to give further details of the operation later in the day.

Last week police made 31 arrests in connection with an alleged plot by an offshoot of 'Ndrangheta to take control of Rome's cocaine trade.

Secrets revealed: Italian police have deciphered a mysterious document written in a code to reveal that it is an initiation rite into the 'Ndrangheta mafia which is based in Calabria (above)

Renowned: The 'Ndrangheta was thrown into the spotlight recently after it was found that the Grillo sisters (above), Nigella Lawson's former personal assistants hailed from a Ndrangheta family

Police were able to move in on the Roman operation thanks to a testimony from one of the four men arrested for Femia's murder, reported The Local Italy.

To extend its reach over the city's drug market, the 'Ndrangheta formed a hit squad to shoot dead a rival mob boss two years ago, police added.

'The 'Ndrangheta considers Rome an integral part of its criminal project. Some members have said: 'Rome is the future',' anti-mafia magistrate Michele Prestipino said.

'The Rome marketplace is strategic and helps the clans accumulate criminal and economic power.'

The group had logistical bases in Genoa, Milan and Turin, and sent representatives to liaise with the most violent Colombian cocaine cartels, Finance Police Commander Cosimo Di Gesu said.

With businesses struggling to survive during six years of on-off recession in Italy, mafia groups have grown in Rome and other parts of Italy not normally associated with organised crime.

Officers had seized more than half a ton of cocaine and cannabis, an arsenal of firearms, and a notebook detailing initiations into the mafia group.

The arrests led to police releasing previously-unseen secret footage of secret 'Ndrangheta initiation rites.

New members swore allegiance and took an 'oath of poison' where they pledge to poison or shoot themselves if they betray their brothers.

Italian police have dealt a major blow to the gang as they carried out arrests across the country, with more than forty alleged members and associates detained in Calabria alone