The plant is believed to be the source of an E. coli outbreak in eight US states.

USDA's Food Safety and Inspection Service has now said that it will increase tests on Canadian meat products for salmonella, Listeria monocytogenes and Escherichia coli.

The agency will also audit the Canadian food safety system, and will centre activities on the Alberta plant in question, Rancher's Beef Ltd. of Balzac. It says other establishments that export meat to the US will also be under scrutiny and all meat products will now be held at the border until they test negative for the three pathogens.

Linked outbreak
Products from Rancher's Beef, sold by the Topps Meat Co. were linked last month to an E. coli outbreak that caused illness to 40 people in the United States. Topps was forced out of business after a massive recall of product in September.

Some Canadian meat producers have indicated that they plan to scale back processing volumes and halt exports to the US until they have a better understanding of what is going on, said Ted Haney, president of Canada's Beef Export Federation.

"This is a disruption of trade, a disruption of price and a disruption of production. We don't need this at this time, with the cost of regulation in Canada, the lack of market access in Asia," he said.

He hopes the move is not politically motivated to protect the US beef industry.

At the very least, he said, the action is an unreasonable one that unfairly implies that Canadian testing is not on par with that in the United States. "This simply can't be justified, as if there is a greater risk in Canada?" he questioned.