The Food Standards Authority (FSA) has warned today that evidence surrounding the worsening horsemeat scandal “points to either gross negligence or deliberate contamination in the food chain”.

Yesterday, it was discovered that frozen food supplier Findus sold beef lasagnes that contained 100 per cent horsemeat and it has been claimed that the company was aware of the issue prior to calling for its removal from shop shelves.

According to The Guardian, the firm was aware of the potential problem two days before telling affected stores to remove the ready meals, while Labour MP Tom Watson has suggested this afternoon that the lasagnes may have contained horsemeat since August last year.

Findus has now issued a further apology, saying: “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 horsemeat.

“We understand those concerns, we are sorry that we have let people down.”

Findus added that it removed all of its beef lasagne products on Monday 4th February 2013 while the issue was independently investigated, and the tests proved that horsemeat was present in a number of samples.

The firm concluded: “We do not believe this is a food safety issue but as a precaution, we are asking customers who may have already bought Findus Beef Lasagne to contact our Consumer Care Line for advice and to receive a full refund.

“All other Findus beef products have been tested and are not affected. We are acting to make sure this cannot happen again.”

Earlier this week, Britain‘s top grocers, suppliers and producers took part in a consultation with the FSA, agreeing to publish results of industry meat testing in a bid to restore public confidence in the wake of the scandal.

It is understood that supermarkets Tesco and Aldi have removed products from implicated French food supplier Comigel as a precaution while fears are growing that some meat items may contain the veterinary drug phenylbutazone or ‘bute‘, which is banned from entering the human food chain.

Commenting on the cases of Tesco and Findus, the FSA noted that the products are thought to come from suppliers in Ireland and France respectively, adding that it is working closely with these authorities to understand the root of the problem.

A statement added:”This is a very serious issue.

“The evidence we have about the two cases, of the significant amount of horse meat in burgers and lasagne, points to either gross negligence or deliberate contamination in the food chain.

“This is why we have already involved the police, both here and in Europe.

“In the particular cases of the Findus lasagne and the Tesco burgers, they have been withdrawn from sale. Anyone who has them in their freezer should return them to retailers as a precaution.

“Our priority remains to protect UK consumers.”

The FSA added that it is still safe to eat frozen meat products as “there is no reason to suspect that there‘s any health issue with frozen food in general, and we wouldn‘t advise people to stop eating it.”