Frozen food giant Findus has reiterated its apology over some of its beef lasagne products containing horse meat, after claims that the contamination could stretch back to last summer.
The company said it was "sorry that we have let people down" and confirmed it carried out a full product recall on Monday, two days before DNA tests confirmed that some of its products contained up to 100% horse meat and it alerted the UK's Food Standards Agency.
Professor Alan Reilly, chief executive of the Food Safety Authority of Ireland (FSAI), says it has already been in touch with the food giant.
"The Food Safety Authority has been in touch with Findus and also Tesco's, essentially to try and find out where this product is, the quantities that are on the market," he said.
"Really, our advice to consumers today is to not eat this frozen beef lasagne, and if they have purchased the product, they should take it back and get their money back."
Findus did not respond to claims by UK Labour MP Tom Watson that it sent a letter to retailers on Monday warning that a France-based supplier had told it there may be problems with raw materials delivered since August 1 last year.
A Findus spokesman said: "At Findus UK our first priority is our customers and providing quality products they can trust.
"But we know that many people have been concerned by the news this week that tests have shown that some of our Findus beef lasagne has been found to contain horse meat.
"We understand those concerns; we are sorry that we have let people down."
The Findus spokesman added that the firm "do not believe this is a food safety issue" but that anyone who had bought 320g, 360g or 500g Findus beef lasagne packs should seek a refund.