Twelve people have died and 26 are ill from listeriosis linked to tainted meat from Maple Leaf Foods, health officials announced today.

The Canadian Food Inspection Agency is determining if listeria bacteria was the sole cause of death in half of those deaths. All but one of the listeriosis deaths are in Ontario and one death is in B.C.

Test results announced over the weekend linked the outbreak with meat produced by Maple Leaf Foods that was tainted with the Listeria bacterium.

Meanwhile, a Regina-based law firm says it has been approached by at least 100 people interested in launching a class action suit against Maple Leaf Foods.

Tony Merchant, of the Merchant Law Group LLP, says residents of Quebec, Ontario, Manitoba and Saskatchewan have been in touch with his company, and that lawsuits in each of those provinces will be launched Monday afternoon.

They will cover people who have become ill due after eating meat products from the company's Toronto plant, people who worry about becoming ill and people who have had to throw out recalled food.

If successful, compensation in the suit will vary by category.

Merchant describes the money associated with the lawsuit as "huge," saying it is unlikely the company's product liability insurance will be able to cover the high cost of damages.

Merchant Law Group handles numerous class action lawsuits, including the one launched by shareholders of Hollinger Inc. against media baron Conrad Black.

Earlier today, the federal minister of health warned Canadians to throw away any meat that comes from uncertain origins, in response to the nationwide listeriosis outbreak.

Tony Clement issued the statement after more than 240 Maple Leaf Foods products manufactured at the company's North York plant were recalled over the weekend.

Sandwiches sold at stores in Alberta and Saskatchewan are being pulled off the shelves after the Canadian Food Inspection Agency announced a recall by Lucerne Foods, makers of Safeway and TakeAwayCafe brand sandwiches.

The agency says the sandwiches may contain some of the pre-packaged meat products recalled by Maple Leaf Foods last week.

The outbreak has been linked to tainted meat from Maple Leaf's Toronto facility.

The company's CEO Michael McCain says the company is deeply sorry for the contamination. He has released a commercial that's running across Canada apologizing to the public for the outbreak.

Products with the establishment code of "97 B" printed on the label are the meats affected by the recall. Consumers who have purchased such products can obtain a refund by returning the items to the retailer.

Authorities have matched a strain of listeria bacteria from three meat samples from the plant to bacteria in the outbreak.

McCain has admitted confidence in the brand has been "shaken" by the move. The recall will cost the company an estimated $20 million, its stocks plummeting sharply on Monday after the contamination link was confirmed.

Listeriosis is a rare but potentially serious food-borne illness. Its symptoms include high fever, severe headache, neck stiffness and nausea. Pregnant women, the elderly and people with weakened immune systems are particularly at risk.

Public health officials say they expect the number of cases to continue to grow in the next few weeks as the bacteria has an incubation period of up to 70 days.

A complete list of recalled products is available here.

With files from The Canadian Press