Tesco has taken out full page adverts in national newspapers today apologising for selling beef burgers that contained horse meat as the Food Standards Agency considers taking legal action.

The grocer said it and its supplier had let customers down and promised to find out “what happened”.

Tesco and Iceland sold the burgers in the UK while Dunnes Stores, Lidl and Aldi sold the meat in Ireland, where the Food Safety Authority of Ireland (FSAI) discovered that the burgers contained horsemeat DNA.

Despite the fact their burgers were not found to contain traces of horse meat, grocers Asda, the Co-op and Sainsbury’s have withdrawn burgers as a ‘precautionary measure’.

The FSAI has asked the retailers involved to provide comprehensive information about how the horse meat DNA was found in its produce. It is also considering whether to take legal action against the companies at the centre of the scandal.

The matter was discussed in the House of Commons this morning where environment minister David Heath said the issue of horse DNA being found in beef burgers was “extremely serious”.

“Consumers should have full confidence that food is exactly what it says on the label,” Heath said. “There are strict rules” requiring food to be labelled accurately.”