Ranchers in southern Alberta say they stand to lose tens of millions of dollars if the sudden Chinese ban on Canadian meat lasts for a long time.

Rich Smith of Alberta Beef Producers says Canada sold nearly $50 million in beef to China in the first quarter of this year, making it the country's third largest customer.

Late Tuesday afternoon, the Chinese government announced a halt to all Canadian meat imports after it said it discovered a banned substance in a Canadian pork shipment. Chinese officials said a subsequent investigation also found forged paperwork.

Many observers believe the trade action is simply the latest retaliatory measure for the arrest of Huawei executive Meng Wanzhou, who was detained by Canadian authorities at the request of the United States for alleged financial crimes.

The U.S. is seeking her extradition.

Alberta produces about 70 per cent of the beef in Canada.

(With files from the Canadian Press)