The Government is powerless to impose a ban on meat imports unless beef contaminated with horse meat is found to be a health risk, Environment Secretary Owen Paterson said.
The Food Standards Agency (FSA) has said there is no evidence to suggest the horse meat detected poses a danger to humans, but confirmed that tests have been ordered on products for the veterinary drug phenylbutazone as animals treated with "bute" are not allowed to enter the food chain.
Mr Paterson was speaking after warning that the next set of results on all retailers' and manufacturers' processed beef products could reveal further traces of horse meat.
"There may well be more bad results coming through, that's the point of doing this random analysis," Mr Paterson said. The results, ordered by the FSA, are due on Friday.
Appearing on BBC1's Sunday Politics show, Mr Paterson repeated his vow to get to the bottom of the scandal, which he has suggested is part of an international criminal conspiracy.
He said: "This week obviously we'll be talking to counterparts across Europe, because ultimately this is European Union competence."
But asked if there should be a moratorium on meat imports in the EU, he said: "That is not allowed within the European common market. "If they find there is a product which could potentially be injurious to public health, emphatically, I will take the necessary action."
Asked if he would consider a ban if tests proved there was a food safety risk, he added: "If there is a threat to public health that is allowed within the rules of the European market."
He spoke after the chair of the Environment, Food and Rural Affairs Select Committee backed a ban and urged the public to buy their meat locally.
Conservative MP Anne McIntosh told BBC Breakfast: "I called for a ban on meat (from the EU) last week. I believe there should be a moratorium on the movement of all meat until such time as we can trace the source of contamination." But shadow environment secretary Mary Creagh said she thought banning meat imports was a "knee-jerk reaction".