McColgan's of County Tyrone has been named as the firm that supplied contaminated halal food
The Food Standards Agency will meet suppliers and retailers later to work out how to prevent contaminated food being sold in shops or used in prisons.
Recently traces of pork have been found in halal products for prisoners and horsemeat in supermarket burgers.
The FSA said firms must make sure food contained what it said on the label.
Commons environment committee chairman, Conservative MP Anne McIntosh, told the BBC the recent cases could be just the tip of the iceberg.
Ms McIntosh has also has questioned whether the FSA is fit for purpose.
"The evidence we've heard, it doesn't really sound as if the FSA has got a grip on this whole scandal," she told BBC Radio 5 live.
The recent cases had been discovered by the authorities in the Irish Republic, while the FSA had not found one incident of cross-contamination, she added.
The FSA is investigating whether the contaminated products were distributed more widely across the UK.
Steve Wearne, a director at the FSA, said it had called an urgent meeting "of a range of suppliers" on Monday where it would "stress again the responsibility of all food businesses to ensure the food that they sell contains what it says on the label".
The FSA tested almost 80,000 samples of food last year, he told the BBC.
"We focus on those risks that can make people ill or worse. So we look for arsenic, listeria and other things that can make you ill," he said.
Frozen burgers McColgan's Quality Foods Limited, based in County Tyrone, has been named as the company that supplied halal food found to contain traces of pork DNA to prisons.
Food distributor 3663 said McColgan's was the source of "the very small number of halal savoury beef pastry products". McColgan's said it was co-operating with the FSA.
Tests were carried out after the manufacturer's name appeared on a report by the Food Safety Authority of Ireland (FSAI) following an investigation which discovered horsemeat in some frozen burgers.
McGolgan's, based in County Tyrone since the mid-1970s, employs about 100 people at its site on the Dublin Road, Strabane.
Under Islamic law, Muslims are required to eat halal food - and eating pork is strictly forbidden.
Halal meat is defined as meat slaughtered by hand and blessed by the person doing the killing, however some Muslims believe mechanised forms of salughter is also now acceptable.
Independent food safety expert Dr Slim Dinsdale told the BBC the British food industry was one of the best regulated, despite these problems.
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