The burgers were sold in Letterkenny Tesco as well as in Dunnes Stores, Lidl and Aldi.
The Food Safety Authority of Ireland said the meat came from two processing plants in Ireland, Liffey Meats and Silvercrest Foods, and the Dalepak Hambleton plant in Yorkshire.
It said they posed no health risk.
Locally-based supermarkets were busy removing the burgers from sale today.
A total of 27 products were analysed, with 10 of them containing horse DNA and 23 containing pig DNA.
Horsemeat accounted for approximately 29% of the meat content in one sample from Tesco. It’s though the beef was IMPORTED into Ireland from eastern Europe.
The chief executive of the FSAI, Professor Alan Reilly, said that while there was no risk to the public, he added that eating horsemeat “was not in Irish culture”.
“Whilst, there is a plausible explanation for the presence of pig DNA in these products due to the fact that meat from different animals is processed in the same meat plants, there is no clear explanation at this time for the presence of horse DNA in products emanating from meat plants that do not use horsemeat in their production process,” he said.
“In Ireland, it is not in our culture to eat horsemeat and therefore, we do not expect to find it in a burger.
“Likewise, for some religious groups or people who abstain from eating pig meat, the presence of traces of pig DNA is unacceptable.”
Tesco has apologised to its customers.
Tesco’s group technical director, Tim Smith, said his company was informed of the test results by the FSAI today and they “immediately withdrew from sale all products from the supplier in question”.
In Tesco’s case, two frozen beef burger products were found to contain horse DNA.
In a statement, Mr Smith said: “The safety and quality of our food is of the highest importance to Tesco. We will not tolerate any compromise in the quality of the food we sell. The presence of illegal meat in our products is extremely serious.”
He added that Tesco was “working with the authorities in Ireland and the UK, and with the supplier concerned, to urgently understand how this has happened and how to ensure it does not happen again”.
“We will not take any products from this site until the conclusion and satisfactory resolution of an investigation,” the statement added.
Customers who may have bought burgers in recent days and weeks can return them to the store where they bought them for a full refund.
Tesco said that the brands affected in its stores are the Tesco Everyday Value brand and Flamehouse Chargrilled Quarter Pounders.
Aldi said it has removed the Oakhurst brand of beef burgers and customers can receive a refund if they purchased any of the products.
Lidl and Dunnes have yet to name their burgers.
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