The Food Standards Agency has said it will continue testing products "until there's nothing left to find" after the veterinary painkilling drug phenylbutazone - or bute - was found in Asda Smart Price Corned Beef.
The agency's director of operations Andrew Rhodes said customers should not eat the corned beef but added anyone who does is very unlikely to fall ill.
He advised customers to return the product to the supermarket to receive a full refund.
Chief Medical Officer Professor Dame Sally Davies has previously said that 'bute' poses only a very low risk to humans. She said:
Asda is recalling all corned beef products from its budget range after traces of veterinary drug phenylbutazone were found in some batches.
The Food Standards Agency said "very low levels" of the painkilling medicine, known as bute, were detected in the Asda Smart Price Corned Beef.
Customers who have bought the 340g tins, with any date code, have been urged not to eat the corned beef but to return it to the supermarket.
Animals treated with the veterinary drug phenylbutazone - or 'bute' - are not allowed to enter the food chain as it may pose a risk to human health.
- Bute was banned from use in humans after it was found that about 1 person in 30,000 recipients suffered a serious side effect.
- Bute can cause rare cases of a serious blood disorder, aplastic anaemia.
- In levels reported in previous FSA testing of contaminated meat, the maximum level found would have to be multiplied a thousand-fold to be at the same level as which used to be given to humans.
- It suggests that even if someone eats contaminated meat, the risk of damage to their health is very low.