Officials have said there is no risk to public health from the tainted foods. But the suspected fraud has caused particular outrage in Britain, where many view the idea of eating horsemeat with distaste, and exposed flawed food controls.
Ministers from the worst-affected EU nations met in Brussels on Wednesday to discuss their response to the scandal, which erupted after tests in Ireland showed products labelled as beef contained up to 100 percent horsemeat.
"This is impacting on the integrity of the food chain, which is a really significant issue for a lot of countries. Now that we know this is a European problem, we need a European solution," Irish farm minister Simon Coveney told reporters as he arrived for the meeting.
Britain's farm minister said the type of tests that revealed the problem should be carried out routinely in future.
"I would like to see DNA testing of processed meat products during process and as finished products established as soon as possible right across every member state," Owen Paterson said.
Both ministers urged EU authorities to propose changes to labelling rules that would force producers to give the country of origin on processed meat products. Currently the requirement only applies to fresh beef, and will be extended to fresh lamb, pork and poultry from Dec. 2014.
The European Commission, which oversees EU labelling rules, said it was studying the option. But officials have warned privately that the complexity of supply chains would make this almost impossible to implement.
EU and national authorities are still trying to uncover the source of the suspected fraud.
"All those countries through which this meat product has passed of course are under suspicion," EU health commissioner Tonio Borg told a news briefing on Wednesday. "By the countries, I mean the companies in those countries which dealt with this meat product."
He added that it would be unfair at this stage to point the finger at any organisation in particular.
NOT JUST HORSE?
On Jan. 15 routine tests by Ireland's Food Safety Authority found horsemeat in frozen beef burgers produced by firms in Ireland and Britain and sold in supermarket chains including Tesco, Britain's biggest retailer.
Concerns grew last week when the British unit of frozen foods group Findus began recalling packets of beef lasagne on advice from its French supplier Comigel, after tests showed up to 100 percent of the meat in them was horse.
The affair has since implicated operators and middlemen in a host of EU countries, from abattoirs in Romania and factories in Luxembourg to traders in Cyprus and food companies in France.
Germany said it was investigating a consignment of beef lasagne sent from Luxembourg to an unnamed retailer in North Rhine-Westphalia on suspicion it might contain horsemeat.
The first evidence that the labelling scandal could go beyond horsemeat also emerged, as upmarket British grocer Waitrose said its testing found that some of its frozen British beef meatballs might contain pork.
The firm, part of the John Lewis Partnership, has withdrawn the product from sale.