A ban on importing meat would not be allowed within the rules of the EU, but could be brought in if beef contaminated with horse meat is found to be a health risk, environment secretary Owen Paterson says.
Although no danger to humans has yet been found in eating the horse meat so far detected, Mr Paterson said that if further tests find it does pose a risk he would "take the necessary action".
The Food Standards Agency (FSA) has said there is no evidence to suggest the horse meat is a food safety risk 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 incompetence."
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."