WINNIPEG, Manitoba (Reuters) – Twelve people have now died out of 26 confirmed cases of food poisoning linked to deli meats produced at a plant owned by Maple Leaf Foods Inc, Canadian health officials said Monday.

There are another 29 suspected cases of listeriosis, officials told reporters, and Agriculture Minister Gerry Ritz said the government expected more cases in coming days.

Maple Leaf Foods, one of Canada’s biggest meat processors, had said it hoped to reopen the Toronto plant associated with the outbreak on Tuesday, but health officials said they will test and hold all meat produced there until they are satisfied it is not contaminated.

“The timeframe really isn’t theirs. It belongs more to the (Canadian Food Inspection Agency),” Ritz said.

Maple Leaf has voluntarily pulled about 220 products made at the plant in one of the biggest food recalls ever in Canada, with direct costs to the company of about C$20 million ($19 million).

Listeria bacteria with the same genetic fingerprint as that found in the ill people was found in two beef products made at the plant. Those products and about 20 others made on the same lines were recalled last week.

Listeriosis, an illness that is particularly dangerous for pregnant women, the elderly, infants and people with weak immune systems, was a contributing factor in seven of the deaths, the Public Health Agency of Canada said.

Five others had the bacteria in their system, but the causes of their deaths are still under investigation, said the agency’s Mark Raizenne.

Previously, four deaths had been attributed to the outbreak.

Maple Leaf has said it’s unlikely it will be able to determine how its meat was contaminated, explaining that the listeria bacterium is common and pervasive.

“It’s very, very, very difficult, if not impossible, to pinpoint a cause,” Chief Financial Officer Michael Vels told analysts on Monday before the latest health announcement.

“I don’t know how important that is to consumers. I think our perspective is what’s more important (as) we let them know what’s going on and we take swift and conservative action to safeguard their health,” Vels said.

Maple Leaf is double-checking procedures at all of its 23 plants but has no reason to believe any other products are at risk of contamination, he said.

Reimbursing customers for returned products, cleaning the plant and other direct expenses will cost the company C$20 million before taxes, Vels said.

On top of the company’s initial cost estimate, it may face reduced sales and increased advertising costs, he said.

“No definitive link has been made between the listeria causing the illness and deaths, and Maple Leaf products,” Vels told analysts.

But a lawyer known for aggressively pursuing class action lawsuits, including against tainted pet food maker Menu Foods Income Fund, said his firm will take action against Maple Leaf.

“It’s apparent, immediately, that the company has been downplaying the significance of what’s going on,” Tony Merchant said in an interview with CTV News.

($1=$1.05 Canadian)