Other major export destinations include Hong Kong, China and the Netherlands.

Experts from countries that may have received tainted pork shipments are expected to meet on Tuesday.

Cancer causing

Dioxins are toxic chemicals that can have serious health effects, including causing cancers, following long-term exposure to them at high levels.

"You would have to be eating products containing these chemicals for 40 years before you would show any signs of illness"

Alan Reilly, deputy chief of Irish food authority

Alan Reilly, the deputy chief executive of the Food Safety Authority of Ireland, said dioxin levels found in meat samples were between 80 and 200 times above the legal limit but stressed the risk to the public was "very, very low".

"You would have to be eating products containing these chemicals for 40 years before you would show any signs of illness," he said.

Britain's Food Standards Agency also said it did not expect any significant risk to British consumers.

Irish government officials described the recall – which affects all pig products produced since September 1 - as a precautionary move.

The Irish food authority said the dioxin made its way into the food chain after pig feed from a producer was tainted with industrial oil, affecting about 10 per cent of the country's pork.

The contamination spread after the tainted pork was processed and mixed with other meat.

The crisis spread to the UK on Sunday as the government of Northern Ireland announced that nine farms in the province had used the same tainted feed.

Brian Cowen, the Irish prime minister, said "the problem has been located" and added that it was important his government took "whatever measures are necessary" to rebuild confidence in the industry.

"The continuing examination and inquiries will proceed and we must take action to reinforce confidence to the public, and obviously also allow the industry to move on from this point."

But Irish farmers called the product recall a nightmare for the country's $570m pig industry, describing it as an "absolute disaster" in the run-up to the Christmas holidays and a "huge blow to the industry".

"We're actually reeling in shock at the moment at the scale of this disaster," Tim Cullinan, an official with the Irish Farmers' Association and a pig farmer, told Irish state radio RTE.

"It couldn't have come at [a] worse time, the weeks leading up to Christmas. ... It's a nightmare."