MONTREAL -- A disgraced Montreal bureaucrat told a public inquiry Wednesday why he never reported the rampant corruption he witnessed at city hall: It wasn't his job.

Gilles Surprenant, a retired city engineer, took to the stand for a fourth day and was questioned about hundreds of thousands of dollars he received in kickbacks on rigged sewer contracts.

He had earlier admitted to receiving $600,000 but, upon being grilled about 91 contracts by inquiry counsel, the actual tally appeared to be more than $700,000 in kickbacks through 2008.

Surprenant said the inflated prices on projects was well known in his office and everyone was aware -- from his own bosses right down to low-level administrative assistants.

He was asked by inquiry counsel why he didn't do anything to stop the system.

Surprenant replied that he spoke to his bosses about it but didn't press further. He said it wasn't up to him to go to the police or blow the whistle publicly.

"I don't think it was my role, as a simple functionary, to call the police about it," Surprenant said.

"My bosses were aware of the situation and, as I've said, for nine years there was not much that was done."

Surprenant said no one at the City of Montreal was pleased about the rampant collusion, which he said was worst between 2000 and 2009. But he said no one did anything to stop it, and his superiors signed off on his work.

He called the inflated contracts an "open secret" in the city's infrastructure department.

"I wanted a normal career like all engineers. I did not want a system like that, I did not need a system like that," Surprenant said, adding that he didn't even know what to do with his ill-gotten gains.

He reminded the inquiry that he returned a good portion of the money. Surprenant recently gave nearly $123,000 to authorities, and he says he lost more than $250,000 at the casino -- which he calls his way of reimbursing the state for the money he took.

The rest he spent on his children and renovations on his house. Also, about $150,000 went to help a construction boss who has having money problems and it wasn't recouped before that man's death.

"I've said it and I'll repeat it: the money that I had, I didn't know what to do with it and I gave back a large part of it," Surprenant said.

The inquiry heard that his kickbacks from some companies started drying up around 2006. He fell out of favour with certain companies after the bids he rigged failed to get approval.

A construction boss told Surprenant he was useless.

Surprenant says he suspects a higher-level city official had become corrupted by that time. An auditing firm had also been taking a second look at contracts.

"I was told that my services were no longer required and I have to say that I was not unhappy with the situation," Surprenant said.

Surprenant continued receiving payments from some companies.

He says he helped fix contracts until 2009, the year he retired from his $82,000 a year city job. He did so in his final year of service even without knowing if he'd be getting a kickback. He was informed there would be no more money for him.

Surprenant denied retiring because of the creation of a provincial police anti-corruption squad; he said it might, at most, have influenced his decision. Surprenant said he'd been considering retiring for a few years and his daughter's illness, with kidney problems, helped make his decision.

In earlier testimony Wednesday, he tried to pin the blame on construction bosses.

"I'm not a villain. I am a civil servant who has been corrupted," Surprenant said, emphasizing that the corruption originated with contractors themselves.

"At the beginning, a corrupt official -- in my case anyway -- does not exist. A functionary becomes corrupted," he said.

The commission spent a second day looking at 91 contracts Surprenant helped draw up. The contracts were tendered between 2000 and 2009 -- an era when the price of public-works projects rose exponentially, by as much as 35 per cent in some cases.

Surprenant said contingency funds on those projects were drained completely, with proceeds from inflated expenses split between contractors and city engineers. It was a practice he was aware of but he didn't know what kind of cut other city employees were receiving.

Describing the false extras, Surprenant cited a project where a contractor was paid $175,000 for digging up ground that wasn't there.

As inquiry counsel Denis Gallant dryly noted, the contractor was paid for "excavating air."

Surprenant had, in most of those 91 cases, taken a kickback himself that ranged from a few thousand dollars to as much as $22,000. The retired engineer was also showered with gifts such as tropical golfing holidays, hockey tickets, wine and fancy holiday dinners.

Surprenant has also described golfing on two occasions with Vito Rizzuto, the notorious Mafia boss, including on a one-week golfing trip in the Dominican Republic in 1996 or 1997.