Suppliers in continental Europe are suspected of being the source of horse meat found in beef products, a processing firm has claimed.
Scientific tests found traces of horse DNA in burgers on sale in some of the UK and Ireland’s leading supermarkets.
The Food Safety Authority of Ireland (FSAI) found low levels of horse in beef products sold in Tesco, Lidl, Aldi, Iceland and Dunnes Stores.
Burger products which tested positive for horse DNA were produced by Liffey Meats and Silvercrest Foods in Ireland and one UK plant, Dalepak Hambleton.
Silvercrest, a subsidiary of ABP Foods, said it was pulling products from sale and replacing them with new lines.
“Following tests carried out by the Food Safety Authority of Ireland, we have been alerted to frozen beefburgers which contain porcine and equine DNA,” said a spokesman.
“Although the products pose no risk to public health, Silvercrest has taken immediate action to isolate, withdraw and replace all suspect product.
“Silvercrest has never purchased or traded in equine product and has launched a full-scale investigation into two continental European third party suppliers who are the suspected source of the product in question.”
According to the research by the FSAI, one sample - Tesco Everyday Value Beef Burgers - showed about 29% horse meat relative to beef content.
Professor Alan Reilly, chief executive of the FSAI, said there was no health risk but also no reasonable explanation for horse meat to be found.
“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 horse meat in their production process,” Prof Reilly 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.”
The retailers have told food safety chiefs they are removing all implicated products from their shelves.
Prof Reilly said traces of other meats would be unacceptable for people who may not eat certain food on religious grounds.
The FSAI analysed 27 beefburger products with best before dates from last June to March 2014 with 10 of the 27 products - 37% - testing positive for horse DNA and 85% testing positive for pig DNA.
Some 31 beef meal products such as cottage pie, beef curry pie and lasagne were tested, with 21 found to be positive for pig DNA. All tested negative for horse meat.
Another 19 salami products were tested but showed no signs of horse DNA.
The FSAI analysis also found traces of horse DNA in batches of raw ingredients, including some imported from the Netherlands and Spain.
Offending burgers had been sold in Tesco stores in Ireland and the UK.
Tim Smith, group technical director at Tesco, said: “Today we were informed that the Food Safety Authority of Ireland (FSAI) has found that a number of beef products they have recently tested contained horse DNA.
“These included two frozen beefburger products sold by Tesco in both the UK and Ireland. Products sold at other retailers were also discovered to contain horse DNA.
“We immediately withdrew from sale all products from the supplier in question. We are 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 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.
“Our customers have the right to expect that food they buy is produced to the highest standards.
“The relevant authorities have said that these findings pose no risk to public health. We understand that many of our customers will be concerned by this news, and we apologise sincerely for any distress. Our customer service team is standing by to answer any questions customers may have.”
Aldi said it was conducting its own investigation.
“We have sought information from one supplier, Silvercrest, which is dealing directly with the FSAI on the issue that has been raised,” the company said.
In a statement, Lidl said it has taken the decision to remove all implicated products from sale pending a full investigation.
“A refund will be provided to customers who wish to return affected products,” said a spokesman.
The Irish Farmers’ Association, which is holding its AGM in Dublin, said it was very concerned at the findings.
John Bryan, president of the organisation, demanded the Department of Agriculture urgently investigate the matter.
“Nothing or no-one can be allowed compromise the high standards and reputation of Irish-produced food,” he added.
Simon Coveney, Ireland’s Agriculture and Food Minister, said the source of the food alert appeared to be companies in the Netherlands and Spain.
“What seems to have happened here is that the extra ingredient that was added was imported,” he said.
“There is no evidence to suggest that Silvercrest knowingly imported ingredients that had horse meat in it.”
Paul Finnerty, chief executive at Silvercrest, said the controversy was extremely disappointing for the company, retailers and consumers.
“We don’t buy any horse meat, and the product in question from the suppliers, that’s being examined at the moment,” he told RTE Radio.
“It will take two or three days to get to the bottom of that.”
Silvercrest said it had taken about 10 million burgers out of the marketplace as a result of the alert.
It also said the product at the centre of the scare and used as an ingredient in the burger mix was supposed to be a beef product rather than rusk, onion or other non-beef bulking agent.
The first samples from burgers were taken in November and second samples were taken later that month when horse DNA was found. Samples were sent to Germany for verification.
In December the FSAI asked Ireland’s Department of Agriculture to take extra samples from ingredients being put into burgers in processing plants.
FSAI got the final verified results on January 11 and inspectors were sent into plants.
“The FSAI were very thorough in terms of testing and retesting and verification of results outside of Ireland,” he said.
The Department of Agriculture takes 30,000 food samples for testing from processing plants in Ireland each year. Silvercrest would have been audited once a month by Department of Agriculture staff.
Mr Coveney accepted there would be serious consequences if it turned out a processor was aware it was using ingredients containing horse meat.
“The primary responsibility here is with the company concerned. And my clear understanding is that the supplier concerned is no longer there,” he said.
Meanwhile, the UK’s Food Standards Agency (FSA) said it had launched its own inquiry.
“The FSA has been in contact overnight with the retailers and producers named in the FSAI survey and has called a meeting this afternoon with a wider range of food industry representatives to discover the extent of the potential problem and to investigate how this contamination might have occurred,” it said in a statement.
Prime Minister David Cameron said retailers had to take responsibility for what was a “completely unacceptable state of affairs”.
He told MPs he ordered the FSA investigation into the “extremely disturbing” case.
“This is a completely unacceptable state of affairs,” he said.
“They will be meeting retailers and processors this afternoon. They will be working with them to investigate the supply chain.
“But it is worth making the point that ultimately retailers have to be responsible for what they sell and where it has come from.”
A spokesman for Dalepak said the firm was currently conducting independent tests on its products.
He said: “Analysis is taking place right now but we won’t have more information until that analysis is complete.”
He added that it was not known how long the tests would take.