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 today.

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 yesterday 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".

Frozen foods firm Findus, which has taken its beef lasagnes made by French food supplier Comigel off shelves after some were found to have up to 100% horse meat in them, said it was considering taking legal action against its suppliers as an internal investigation "strongly suggests" that the contamination "was not accidental".

The company said in a statement: "Findus is taking legal advice about the grounds for pursuing a case against its suppliers, regarding what they believe is their suppliers' failure to meet contractual obligations about product integrity."

Mr Paterson said no case for criminal action has been discovered in the UK yet but the FSA said it is "working closely" with police in case that changes.

The scandal has spread all over the continent as details of the elaborate supply chain in the meat industry emerge.

French consumer safety authorities have said companies from Romania, Cyprus and the Netherlands as well as its own firms were involved.

Romanian authorities have confirmed they are investigating while their Dutch counterparts said they are ready to do so if necessary.

Beef products suspected of containing horse meat have also been withdrawn from shops in Ireland, Sweden and France.

Findus said it carried out a full product recall last Monday, two days before DNA tests found that some of its lasagnes contained up to 100% horse meat.

The firm, which has its headquarters in London, tested 18 of its beef lasagne products made by Comigel and found that 11 contained in the range of 60% to 100% horse meat.

Tesco and Aldi have also withdrawn a range of ready meals produced by Comigel over fears that they contained contaminated meat.

Mr Paterson said yesterday that retailers have agreed plans to improve their food testing, adding that they hold the "ultimate responsibility" for making sure their products do not contain horse meat.

He spoke after attending an emergency summit with bosses from leading supermarkets, trade bodies and the FSA to discuss the scandal which has seen other chains including Lidl and Iceland withdraw some products.

He said supermarkets and trade bodies have already begun plans to carry out more testing and report their results on a quarterly basis.

Mr Paterson added: "It's a question of either gross incompetence, but as I've said publicly and I'll repeat again, I'm more concerned there's actually an international criminal conspiracy here, and we've really got to get to the bottom of it.

"If there's a criminal act we will work with the authorities wherever they are to ensure the appropriate measures are taken.

"This is a conspiracy against the public. Selling a product as beef and including a lot of horse in it is fraud."

There have also been fears that contaminated meat has been served to people in hospitals, schools and those who use meals-on-wheels services, with the Local Authority Caterers Association saying it was "as sure as we can be that this is not affecting the school catering area".