All production has been halted at an Irish factory discovered to have produced beef burgers containing horsemeat
Silvercrest Foods County Monaghan announced it has suspended operations indefinitely pending further investigations into how its products were contaminated.
Ten million burgers have been removed supermarket freezers across Ireland (OTC BB: IRLD - news) and the UK and are now expected to be destroyed after Irish authorities found they contained traces of horse DNA.
Silvercrest has said it believes the source of the contaminated material is one supplier on the continent.
In a statement it said: "Because equine DNA has been found in finished products tested this week, we have decided that the responsible course of action is to suspend all production at the Silvercrest plant in County Monaghan with immediate effect."
Ireland's agriculture minister, Simon Coveney, confirmed that seven samples of raw ingredients in the burgers were tested for horse DNA, including one from another European country which tested positive.
All ingredients in the production of burgers sourced from Irish suppliers tested negative.
Mr Coveney described the contaminated ingredient as a powdered beef-protein additive used to bulk up cheaply produced burgers with relatively little meat.
Mike Gibney, director of the Institute of Food and Health at University College Dublin, said the drive to cut prices could have contributed to the problem as beef is three to four times more expensive than horsemeat, which is primarily used in pet food.
He said: "As you push down the price of the producer, they push down the price of their supplier, there you get into the danger.
"You might find a supplier cutting costs and putting ingredients in there that shouldn't be in there."
Silvercrest's parent company, ABP Food Group, has said it will introduce DNA testing in its production lines and has sent investigators to the production plants of all its ingredient suppliers.
Irish authorities have repeatedly stressed there are no safety concerns over the use of horsemeat in the burgers.
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