The trial of 46 alleged mafia members has kicked off in Rome, opening the next saga of a yearlong investigation that has already exposed politicians, businessmen, and other officials reportedly involved in the embezzlement of millions of euros from city hall contracts.

Among the defendants is a former neo-fascist gangster with one eye, who is a member of Rome's notorious far-right Magliana Gang. Investigators say Massimo Carminati, allegedly dubbed "the last king of Rome," and his sidekick Salvatore Buzzi, a convicted murderer, are at the head of the crime ring that prosecutors say ran far beyond traditional Mafia areas of extortion, foraying into activities deeply rooted in systemic corruption, including rigging public tenders on everything from creating refugee centers to rubbish collection.

Both men deny the charges against them, including a connection to any mafia. The men will appear via video link in court from the high-security jails where they have been detained. The trial is expected to last through July 2016.

"In this whole story, the thing which has really annoyed Carminati is the fact that his name has been associated with the words mafia and drugs. He has nothing to do with the mafia," his lawyer Giosue Naso told reporters outside the courthouse.

During the investigation, prosecutors obtained some 36,000 hours of wiretaps to back up their case, according to Italian media. Investigators also secretly filmed video showing some of the accused receiving bribes and discussing how they manipulated the system.

An initial, fast-tracked trial tied to the scandal ended on Tuesday, with four defendants found guilty and handed prison terms of between four and five years. The judge agreed that the graft mechanism represented a genuine organized crime network.

Police say the network operated like a mafia clan, but independently of established southern Italian mafias such as Sicily's Cosa Nostra, the 'Ndrangheta in Calabria, and Camorra in Naples.

Prosecutors allege that mobsters flourished in Rome following the 2008 election of right-wing mayor Gianni Alemanno, who is under investigation for graft, but does not face any mafia-related charges and is not involved in this trial.