An Irish meat processor recalled 10 million burgers on Wednesday from supermarkets across Ireland and Britain amid fears that many could contain horsemeat, a discovery that poses no danger to public health but threatens to undermine the beef business central to Ireland's rural economy.
Silvercrest Foods, Ireland's second-largest processor of beef burgers, took the action after the Food Safety Authority of Ireland revealed that DNA tests of patties on sale found tiny traces of horsemeat in more than a third.
Experts said the finding was not surprising, given that meat refrigeration units and slaughterhouses would handle multiple kinds of meat and molecular transfers were inevitable.
But investigators were surprised to find that one burger among 27 tested contained 29 per cent horsemeat. Tesco, the British supermarket giant that sold the discount burger brand in question, apologised and said either fraud or incompetence was to blame.
Silvercrest and government leaders said suspicion was focusing on a powdered beef-protein additive imported from both Spain and the Netherlands for use in padding out the most cheaply priced burgers, which contain typically 60 per cent to 70 per cent meat.
They declined to identify the supplier by name because investigations were continuing, and a multimillion-dollar lawsuit for damages was likely.
"There is a full investigation going on as to how the imported additives got into the system and where they came from. This is very important for Ireland's reputation," Prime Minister Enda Kenny told reporters at the European Parliament in Strasbourg, France.
Health authorities stressed Ireland's policy of occasionally DNA testing food was exceptional, given that most countries don't bother checking for non-health issues in food at all.
They said such testing, if repeated worldwide, would likely find much more widespread mislabelling of meat and fish products and traces of the "wrong" meats in processed foods.
In 2011, for example, a DNA study by the Food Safety Authority of Ireland found that three-quarters of fish labelled as cod in Irish fast-food outlets was actually one of several more cheaply sourced fishes, including pollock, hake or haddock.
Likewise, experts said the horsemeat finding suggests possible consumer fraud because horsemeat costs less than a third of its beef equivalent.
"If you buy a chicken fillet, there's nobody checking that it isn't a seagull fillet. That's not a criticism of Ireland. This sort of species testing simply isn't done in other countries," said Patrick Wall, professor of public health at University College Dublin and former chairman of the Food Safety Authority for the entire 27-nation European Union.
Wall said the Irish agency's food fraud unit was right to use DNA techniques to identify if meat ingredients were honestly listed, even though negative findings could fuel consumer panic.