02/20/2013 02:36 EST | Updated 04/21/2013 05:12 EDT

E. coli found in frozen burgers triggers another widespread beef recall

OTTAWA - Health officials are investigating another massive cross-country beef recall after frozen burgers sold by Canada Safeway Ltd. tested positive for E. coli bacteria.

Health officials are testing several Safeway brand burgers including Gourmet Meat Shoppe Big & Juicy Burger, Gourmet Meat Shoppe Prime Rib Burger and Butcher's Cut Beef Patties sold in packages of 10, 20 and 40.

The burgers were produced on one single day on Aug. 14, 2012 at the Cardinal Meat Specialists plant in Brampton, Ont. The burgers have a best-before date of Aug. 14, 2013. The plant will continue to operate during the investigation. Cardinal is the biggest meat producer in Canada, according to the Canadian Food Inspection Agency.

"They've taken the precautionary action of recalling all the products produced on the line for that day and we're continuing to work with them in the investigation," said Paul Mayers, associate vice-president of programs at CFIA.

Federal inspectors are examining retail samples of the products and received a positive response for E. coli. The investigation was sparked after two people in Ontario and Manitoba became ill and tested positive for E. coli on Feb. 13.

Another E. coli scare in December 2012 caused a recall and investigation of a different brand of burgers produced by Cardinal Meat Specialists. Health officials found no evidence of contamination in the plant.

Safeway Food Ltd. called for a voluntary recall of beef patty products that were distributed to stores in Ontario, Manitoba, Saskatchewan, Alberta, British Columbia and the Northwest Territories. Just how many of the patties were sold is not yet known.

Widespread E.coli contamination in beef products from the XL Foods plant in Brooks, Alta. last September and October led to the temporary shut-down of the plant and a nationwide recall.

Health officials believe the illnesses may have been linked to Safeway burger patties and are awaiting test results. In the meantime, they have launched an investigation in to the safety procedures and the ingredients, which come from Canada and abroad.

Food contaminated with E. coli may not look or smell spoiled, but is potentially deadly. Health officials say it can cause bloody diarrhea, dehydration, and in the most severe cases, kidney failure.