The Irish Minister for Agriculture, Food and the Marine, Simon Coveney, said yesterday in a statement that his department has received a test result confirming 75 percent equine DNA in a raw material ingredient at Irish food company Rangeland Foods, in the county of Monaghan.

Since the food-standards scandal first began to unfold, horse meat has been detected in frozen beef burgers sold in some of Britain’s biggest supermarket chains, including Tesco, Lidl, Aldi and Iceland, according to the BBC. The largest proportion to date was found in Tesco Everyday Value Beef Burgers, where horse meat represented 29 percent of the total.

Ireland’s Food Safety Authority and the British Foods Standards Agency have been conducting further inquiries to establish whether Polish-labeled product has been used in other meat processing plants in Ireland.

RELATED: Horse meat discovered in frozen beef burgers in UK

Rangeland Foods notified the Department of its use of Polish meat ingredients in the manufacture of certain burger lines last Thursday evening due to the suspicion of the presence of equine DNA, according to reports from the Associated Press. The Department took samples of the material concerned from the plant to test for the presence of equine DNA. Given the results, production has been suspended at Rangeland Foods pending the outcome of the investigation.

The investigation is focusing on the full supply chain including the meat trader concerned and others who facilitated the purchase of the product and its transfer to users in Ireland. The Department says it is in continuing contact with Polish authorities as the investigation has shown that all implicated raw material ingredient is labeled as Polish product.

DNA results last month on a wide range of factory-made burgers in Ireland found more than a third contained at least a trace of horsemeat – and two, manufactured for the British supermarkets Tesco and Co-op, contained 29 percent and 18 percent horsemeat respectively. British officials said they feared that such horsemeat-tainted burgers had been on sale since mid-2012, said the Huffington Post.

It wasn't determined whether the latest results represent a higher level of horsemeat than detected in earlier tests, given that the initial DNA tests were on finished burgers while the latest pinpointed the volume of horsemeat in the imported Polish ingredient itself. The Polish product was labeled as beef offcuts – slaughterhouse leftovers – that the Irish plants used as cheap filler material in budget-priced burgers.

According to Associated Press, Coveney says police have joined Ireland's three-week-old investigation into why horsemeat has been detected in some Irish-produced burgers and the chief suspect, Poland, has yet to supply any adequate explanation.

Polish authorities, fearful that their own lucrative meat-export markets could be damaged, insist their own testing of slaughterhouses implicated by Ireland has not turned up any evidence that any of them handled horsemeat.

Heretofore, economic damage from the unfolding scandal has focused on the Silvercrest processing plant, also in Monaghan, identified as the primary producer of horsemeat-tainted burgers. Its operations have been suspended and it has lost contracts worth more than €45 million annually, according to published reports.