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.
More top news
The current and former First Ladies praised one another's record and experience - before criticising Republican Donald Trump on both fronts.
After Twitter announced it is to axe its video sharing service Vine, we took a look at some of the more memorable six second video clips.
Three people have been arrested and charged in connection with violence between West Ham and Chelsea fans at the former Olympic stadium.