MONTREAL -- A disgraced Montreal bureaucrat says it wasn't his job to stop corruption at city hall, even if he knew it was going on.

Gilles Surprenant, a retired city engineer, is on the stand Wednesday for a fourth day at an inquiry where he is discussing kickbacks he took on rigged sewer contracts.

Surprenant said the inflated prices were well known in his office -- and everyone was aware, from his own bosses 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 he 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 that 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 appreciated the rampant collusion but no one did anything to stop it during the era where the practice was most rampant -- between 2000 and 2009.

"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.

Surprenant has already admitted that he pocketed nearly $600,000 in kickbacks over roughly 20 years. While going through each individual contract at the inquiry, tallying up the amounts he got for each one, the amount appears to be higher than that.

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 began to dry up around 2006. Contractors were no longer soliciting him for help. One boss told him he was useless.

Surprenant said he suspects a higher-level city official had become corrupted by then.

"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 added that he continued to be paid by certain contractors.

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

"The phenomenon of corruption is a phenomenon that originates with the contractors," Surprenant said. "At the beginning a corrupt official -- in my case anyways -- does not exist. A functionary becomes corrupted."

The commission is spending a second day looking at 91 contracts on which Surprenant was involved in planning and drawing up plans.

The contracts all fall 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 had, in most of those cases, taken a kickback 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.

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