MONTREAL -- A Quebec corruption inquiry heard a detailed history of the Italian Mafia on Tuesday -- with everything from its secret codes, its origins, the scope of its reach, to how it got into the construction business.

The inquiry was even shown the so-called "Ten Commandments" of the Sicilian Mafia, the list of rules under which members must supposedly live.

The rules include not staring at a fellow mobster's wife; not hanging out in bars and clubs; and not being seen talking to a police officer. They were listed on a document found by Italian police, according to Tuesday's testimony.

Such information came from Valentina Tenti, who holds a doctorate in criminology and is an expert in the Italian Mafia.

The Italian-born scholar, who is doing post-doctoral work in Montreal, was the first in a series of law enforcement and academic experts who will testify at the Charbonneau inquiry about organized crime in the coming weeks.

The inquiry hopes to uncover wrongdoing in the construction industry, and its links to organized crime and political corruption.

Tenti is providing context about the Mafia in Italy and how its various groups evolved over time, from rural entities to empires with a worldwide reach.

They have survived, she said, thanks to a highly structured makeup and an ability to adapt and spread into legitimate businesses such as construction.

In a 100-page report for the commission on how the Mob infiltrated construction in Italy, Tenti noted that Mafia was largely localized in rural communities but capitalized on the building boom following the end of World War Two.

European countries devastated by the war -- including Italy -- had received billions under the U.S. Marshall Plan.

"At the beginning (the Mafia) entered the market through extortion," Tenti testified.

"They set up companies in specific sectors and they were able in this way to enter the market with a direct involvement in the industry itself."

In an example of just how influential the Mafia was, Tenti said the Sicilian city of Palermo authorized some 4,000 building permits during the boom in the 1950s.

But 2,500 contracts went to just three people -- none of whom knew anything about construction. They were frontmen for Mafia-backed companies.

Mafia-led businesses can be controlled directly or indirectly by crime groups and they resort to violence as a business tactic, she said. The companies also have access to funds from illegal activities and that can give them a competitive edge, she said.

Tenti told the commission that the problem is bad enough in Italy that she helped create software that evaluates the risk of Mob infiltration for public contracts doled out there.

Money is a major part of what drives the Mafia, but not the only thing, she said. Since the 1970s, the illegal drug trade accounts for the majority of money raised, while legitimate businesses and construction are also integral, she said.

But sometimes power over a given territory can, she said, be more important than money.

The practice of the "pizzo," or protection payments from businesses, remains prevalent.

She cited a 2007 study that suggested the Sicilian Mob managed to raise 160 million euros in "contributions" from businesses on that island. It said about 70 per cent of Sicilian businesses paid the pizzo -- with each business dishing out an average of 50,000 euros.

In some Sicilian neighbourhoods as many as 80 per cent paid, believing it was easier to pay up than deal with the aftermath, Tenti said.

She described the Sicilian Mafia, the Cosa Nostra, as having a great capacity for adaptation. It often expands by offering services -- such as protection or financing to companies in need, especially in times of financial crisis. She said it can become an alternative to banks for certain companies in difficulty.

During her presentation, Tenti spoke at length about Italy's three biggest traditional organized crime groups -- the Cosa Nostra (in Sicily), the Camorra (Naples), and the 'Ndrangheta (Calabria).

The Cosa Nostra, or Sicilian Mafia, has long been the dominant Mafia group in Quebec. She said 181 Cosa Nostra families still existed in Sicily in the early 2000s and they remain powerful and "scary."

While there are some romantic myths about the Cosa Nostra she said the 'Ndrangheta, while less known and less visible than its Sicilian counterpart, is no less influential. She said that Calabrian group has a strong presence in Canada -- particularly in Toronto and Thunder Bay, Ont.

They are just as successful financially, she said.

She cited a study suggesting that group made 44 billion euros from various criminal activities, primarily through the drug trade with Colombia.

"That's almost 2.9 per cent of the gross domestic product of Italy," Tenti said.

Mafiosi themselves don't see themselves as "Mafia" -- rather, they view themselves as "men of honour," she said.

"Mafioso are made and not born," Tenti said. "You need to undergo a process, a right of affiliation."

There is a ritual involved in becoming a Mafioso that includes the cutting of a finger and the shedding of blood on a holy object.

She described the Mafia life as, "Come in with blood, go out with blood."

There are also the so-called Ten Commandments of the Cosa Nostra, a list of rights and duties that all mobsters must live by. In addition to forgoing pubs and not fraternizing with police, members must always be available to the Mafia, even if their wife is about to give birth.

Anyone who has family working in law enforcement -- or a "two-timing relative" -- cannot be a member, the document says.

A total of 50 witnesses are expected to be heard this fall, including many law-enforcement experts.