A bolognese sauce produced by Irish food group Greencore for Asda contained 4.8% horse DNA, according to test results released tonight.
The firm, which saw its share price fall by almost 10% yesterday, said it was going to carry out a thorough and comprehensive investigation to determine how its supply chain had been contaminated.
The company, whose CEO is Minister of Agriculture Simon Coveney's brother Patrick Coveney, said they only source products from approved suppliers, which are regularly audited.
Greencore said the sauce contained meat that was supplied by the ABP Food Group's Nenagh plant in County Tipperary.
Asda withdrew the beef bolognese sauce on Thursday night.