TESCO has withdrawn a meatloaf product from sale in Ireland and Britain after it tested positive for horse meat.
The supermarket giant said that its frozen Tesco Simply Roast Meatloaf 600g had between 2pc-5pc horse DNA.
The product was manufactured between October 2012 and January 2013 at Eurostock in Craigavon, Northern Ireland.
"Our investigation to thoroughly understand the source of the contamination has started, and we will complete our investigation before deciding whether to continue using the supplier," said Tesco technical director Tim Smith.
This is the fourth Tesco-branded product to test positive for horse meat.
"We are very sorry that we have had a further product which has failed to meet the high standards we and our customers expect," said Mr Smith.
The retailer has now tested 500 product lines most at risk of containing horse meat.
Eurostock Foods last night issued a statement confirming that meatloaf products from its plant in the North contained horse DNA.
It said it had launched a "thorough and comprehensive investigation into this matter".
Meanwhile, tough new penalties are being planned to deter fraudsters from carrying out scams in the food chain in the wake of the horse-meat scandal.
EU Health and Consumer Commissioner Tonio Borg warned that only the prospect of being fined more than they could earn from their crimes would serve as an effect- ive deterrent to fraudsters.
He urged individual countries to step up their investigations.
The Department of Agriculture said it is planning to publish its report into the horsemeat scandal tomorrow.
The findings of its investigation into Irish companies' role in the scandal are finally set to be released, two months after the scandal broke.