Horse meat has been found in beef burger products, according to the Food Safety Authority of Ireland.
The beef burger products which tested positive for horse DNA were produced by two processing plants, Liffey Meats and Silvercrest Foods, in Ireland and another plant in the UK, Dalepak Hambleton and were on sale in Tesco, Dunnes Stores, Lidl, Aldi and Iceland in Ireland and the UK.
The FSAI findings of horse meat in beef burgers have been described as "unacceptable"
The FSAI said that in nine of the 10 beef burger samples from these retailers, horse DNA was found at very low levels. However, in one sample from Tesco, the level of horse DNA indicated that horse meat accounted for approximately 29% relative to the beef content.
The retailers told the FSAI that they are removing all implicated batches from sale while Silvercrest Foods confirmed it was withdrawing all products from sale and replacing them with new products.
The chief executive of the FSAI, Professor Alan Reilly, said that while the presence of horse meat did not pose any risk to public health, it did raise concerns.
“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 horse meat 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."
Ireland's Minister for Agriculture Simon Coveney told the Irish Farmers' Association AGM that he was "very annoyed" at the discovery of horse meat in burgers and wanted to know "how on earth" a test result of 29% horse meat in a beef burger could come from a factory that does not slaughter horses or buy horsemeat.
The IFA added that the findings were "unacceptable" and added in a statement that "nothing or no-one can be allowed compromise the high standards and reputation of Irish-produced food."
Tim Smith, Tesco Group technical director, said in a statement: "We are working with the authorities in Ireland and the UK, and 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 satisfatory resolution of the investigation.
"We understand that many of our customers will be concerned by this news, and we apologise sincerely for any distress."