A $3.5-billion proposed class-action lawsuit has been launched on behalf of addicted gamblers who allege they asked to be barred from Ontario's casinos, but were still allowed in.

The suit was filed against the Ontario Lottery and Gaming Corporation in Toronto on Tuesday, claiming the corporation did not do enough for those who signed up for "self-exclusion," a program that allows people to have themselves banned from casinos so that they can curb their ruinous gambling habits.

None of the allegations has been proven in court and a statement of defence has not yet been filed in the suit, which has not been certified as a class action. The representative plaintiffs — Peter Dennis and his wife, Zubin Noble, of Markham, Ont. — hope thousands of addicted gamblers will join them in the suit.

Those who sign up for the self-exclusion program are photographed and registered, and their information is stored in binders at every provincial casino. If they are caught trying to enter a casino, they can be arrested for trespassing.

But gamblers who spoke with CBC News on condition of anonymity said the program doesn't work. One woman said she registered for the program, but her gambling addiction led her back to a casino soon after.

"I walked through, no one looked at me," she said. "I kept gambling for the next couple of years."

Lawyers say the OLG should be using high-tech systems to catch self-banned gamblers. In the Netherlands, gamblers present photo identification at casinos, and their identification is checked against a computer database, lawyers say.

Lawyer Jerome Morse of Adair Morse LLP in Toronto, who represents Dennis and Noble, said the suit is designed to help addicted gamblers who have lost large sums of money, and their families. But he also hopes the suit will bring about changes at casinos across the continent.

"[We hope it sets] a precedent that not only benefits all members, but that will benefit anyone who is subject to the dangers of gaming in North America," he said.

Ontario has settled nine individual lawsuits pertaining to self-exclusion, but has never been hit with a large class-action suit.

The OLG has argued in the past that it is ultimately up to the gamblers themselves to stay away from casinos, although the corporation has expressed interest in obtaining facial recognition technology to improve its screening process.