More beef products have been ordered off Canadian shelves this week as food-safety officials explain why an Alberta meat-packing plant at the centre an E. coli scare remained operational for three weeks after the contamination was first detected.

XL Food Inc. issued a voluntary recall of “whole muscle cuts” of beef, including steaks and roasts, on Friday. It was the latest in at least eight recalls that have been issued since Sept. 16.

The stores named in the latest release include Wal-Mart, Food Basics, Metro, Co-op stores and Steakhouse Angus Select.

In Quebec, Marche Richelieu, Marches A-M-I, Metro, Metro F, Metro Plus, Metro Plus F and Super C were added to the list.

The Canadian Food Inspection Agency has warned that further recalls are expected in the days ahead.

The agency temporarily suspended XL Food’s operating license on Thursday, leaving more than 2,000 employeestemporarily out of work.

“To date the company has not properly implemented agreed upon corrective actions and has not presented an accepted plan to address long term issues,” CFIA spokesperson Brian Evans told a news conference in Ottawa on Friday.

All products at the plant are now under the control of the agency and will not be released until they’ve been thoroughly tested, said Evans.

Alberta Agriculture Minister Verlyn Olson acknowledged to reporters Saturday that the recall is “a serious problem.” But he also urged Canadians to continue supporting the province’s beef industry.

“It’s a big plant,” Olson said as he bought ground beef at a grocery store. “There are many other plants. And I really hope that people will support our beef industry by buying beef.”

Earlier this week the United States banned all imports from XL and pulled the company’s beef from stores in 30 states, including Wal-Mart.

The E. coli was first detected on beef imports in the U.S. on Sept. 3 and was brought to the attention of Canadian officials one day later.

Following a number of inspections by CFIA, the agency issued the first recall on XL ground beef products on Sept. 16.

Asked why it took the agency weeks between detecting the contaminated meat and issuing a recall, Evans said there was nothing to indicate that the tainted meat had reached consumers.

 "The primary issue at that time was to identify if, in fact, there was any product in the marketplace that needed to be recalled," said Evans.

"We did confirm that neither the product that we had found through our testing program or the product that the U.S. had identified ... had gone into the marketplace. Issuing a recall for a product that isn't in the public domain isn't something that we're able to do."

Evans said further information triggered another intensive inspection of the plant for a possible problem, which according to officials is the result of several different factors – none of which by themselves would normally pose a problem.

Meanwhile, oppositions critics said changes to the food inspection system implemented by the Conservative governmentare to blame for the E. coli scare.

"The company fell short of proper standards way back in August, and this government's inspection system failed to be on top of it then," Liberal MP Ralph Goodale told the House of Commons.

"Partly, that's because government inspectors don't actually inspect much anymore. They just monitor company inspections."

Agriculture Minister Gerry Ritz insisted that food safety has not been compromised and the XL plant has seen an increase in federal inspectors over the last three years.

The Canadian Cattlemen's Association said XL’s closure will reduce the ability of the industry to slaughter and process live cattle, but it should not have a significant effect on Canada's beef industry, beyond a brief, minor increase in price.

While beef products continue to be pulled from shelves, some farmers are beginning to feel the effects of the E. coli scare.

“Yesterday you were making $1,200 per cow and today you’re going to sell it for $800 or $900,” cattle auction manager Ivan Potts told CTV Edmonton on Friday.

The Canadian-owned XL Foods plant has a slaughter capacity of about 5,000 cattle a day.

With a report from CTV Edmonton and files from The Canadian Press