DUBLIN (AP) -- The Irish meat company at the center of Europe's "horseburger" scandal on Tuesday blamed the contamination of its hamburger patties on the purchase last year of 170 tons of meat imported from Poland.
As Ireland struggled to contain the damage to its reputation as Europe's top beef exporter, the ABP Food Group shed new light on how burgers made partly of horse ended up on British and Irish supermarket shelves. Ireland's biggest beef company said it purchased the Polish meat last year marked as "beef" from an Irish meat trader, McAdam Food Products, and the product was used by its Silvercrest food processing facility to make frozen beef burgers sold across Britain and Ireland.
The company said in a statement to The Associated Press that "while Silvercrest purchased these beef products in good faith, horse DNA originating in Poland was present in some of these products."
Confirmation of the scale of ABP's Polish purchases -- at odds with the company's promise to customers to produce all-Irish patties -- came hours after Irish Prime Minister Enda Kenny vowed that Ireland would pinpoint the source of the horsemeat.
"Clearly this is a matter that has to be sorted out ... a matter of reputation. Obviously we can't afford to have that," Kenny said as he entered a Cabinet meeting focused on efforts in Ireland, Britain and Poland to identify the source.
Poland says its own investigations of slaughterhouses identified by Ireland as suppliers to ABP have produced no evidence they have shipped horsemeat. But experts said since the meat was shipped many months ago for long-term use, tests on current Polish meat shipments could well be pointless.
They also argued that it was still too soon to pin the blame on Poland, because the meat -- considered a delicacy in some countries, but reserved for use in pet food by most -- could have been added to burger-bound beef later in the supply chain. They cautioned that Ireland has a crooked past track record of food-labeling fraud in beef exports.
Kenny likewise hedged his position. Asked whether the suspect meat product might have been misleadingly labeled as Polish by Irish fraudsters, Kenny said, "Clearly plants in Poland have been supplying material, but the evidence might be that other investigations need to take place as well."
The Food Safety Authority of Ireland emphasized that the problem was a matter of honest labeling, not safety, and must involve fraud by a producer or supplier somewhere along the seven-nation journey by truck from Poland to Ireland. The reputational damage to Ireland threatens to erode international confidence in the country's top agricultural product, beef, an export business worth EUR1.9 billion ($2.5 billion) a year to this country of 4.6 million.
Irish police have opened an investigation into whether McAdam knew it was trading in horsemeat. McAdam also sold Polish meat to Rangeland, another maker of frozen beef burgers. Silvercrest, Rangeland and McAdam are all based close to each other in rural County Monaghan.
Agriculture Minister Simon Coveney, who testified Tuesday to lawmakers probing the scandal, said Ireland's two other major producers of frozen beef burgers in other parts of Ireland did not import any meat from Poland.
DNA testing on dozens of frozen burgers in Irish stores commissioned by Irish food safety officials uncovered the apparent fraud.
The first results published Jan. 15 found 29 percent horsemeat content in one Silvercrest-produced burger for Tesco, the biggest supermarket chain in Britain and Ireland, and traces of horsemeat in many other Silvercrest-made burger brands for several supermarket chains in both countries. Subsequent DNA tests by the British supermarket Co-op found another Silvercrest-made burger composed of 18 percent horsemeat.
And on Monday night, Ireland's Agriculture Department said an original batch of the Polish-labeled product found in the deep-freeze storage at Rangeland was 75 percent horsemeat. Hours later across the border in the British territory of Northern Ireland, tests on a similar product at a cold storage unit and earmarked for delivery to Silvercrest was found to be 80 percent horsemeat.
Both Silvercrest and Rangeland have suspended operations. Silvercrest already has lost its major supply contracts with Tesco and Burger King.
Alan Reilly, chief executive of the Food Safety Authority, said the latest findings demonstrated that Ireland was dealing with fraud, not an accidental contamination.
"We're no longer talking about trace amounts of horse DNA in product. We're talking about horsemeat. Somebody, someplace, is drip-feeding horsemeat into the burger manufacturing industry. We don't know yet exactly where this is happening. All the documentary checks that we have on these shipments show that they have come from Poland," Reilly said.