LONDON -- The furniture giant Ikea joined a growing list of brands that have been touched by Europe's food scandal on Monday and withdrew its signature Swedish meatballs from its markets and cafeterias across most of Europe after one batch was found to contain traces of horse meat.
Ikea's decision -- which followed a recall by the Swiss food maker Nestlé last week -- demonstrated that even closely guarded brand names have found themselves vulnerable.
In weeks of tracing the problem, European Union and national officials have conceded that their oversight had not been aimed at authenticating food products. Now that governments and companies have undertaken more extensive testing, the results appear to indicate that food adulteration may be more commonplace and widespread than previously believed.
"Clearly there has been fraud on a massive scale across multiple countries in the E.U.," Simon Coveney, the agriculture minister for Ireland, which holds the union's rotating presidency, told a news conference after a meeting with colleagues in Brussels on Monday.
Noting that "big brands and big names that people trust" have been caught up in the issue, Mr. Coveney said, "We are all eager to get to the bottom of this."
The detection of horse meat, which began in Ireland and spread quickly, has raised questions about the quality and oversight of Europe's complex chain of slaughterhouses, processed meat producers, distributors and retailers.
Already millions of products have been withdrawn, and new cases of adulteration are being discovered almost daily, involving some of the best-known food makers -- including Findus and Iglo -- and most prominent supermarket chains.
Ikea's announcement underlined how few retailers can rest easy as more scrutiny is applied. The recall risks denting the homely Scandinavian image of Ikea, one of Sweden's best-known companies.
A traditional part of Swedish cuisine, meatballs are consumed in huge quantities -- 150 million a year, according to the company's Web site -- by customers in Ikea cafeterias and are also sold for consumption at home.
The company said its action concerned meatballs manufactured by one supplier in Sweden and applies to all European countries except Norway and Russia and to a limited number of products in Switzerland and Poland. The United States is not affected, the company said.
Clive Black, a retail analyst at Shore Capital, an investment banking company in London, said that Ikea's announcement was "another left-field random outcome of the whole situation. Did Ikea want to sell horse meat? No. Have they been caught out by rogue elements? Yes."
"The breadth with which contamination has been found clearly shows that there has been substantial rogue activity," he added.
Ikea first said that it would not sell or serve any meatballs at its stores in Sweden after the Czech authorities detected horse meat in frozen meatballs that were labeled beef and pork, even though Ikea's own tests two weeks ago had not detected horse DNA.
The company also said it was stopping sales in Slovakia, the Czech Republic, Hungary, France, Britain, Portugal, Italy, the Netherlands, Belgium, Spain, Greece, Cyprus and Ireland. The meatballs were produced by Ikea's main supplier of the product, a Swedish company called Familjen Dafgard.
In a statement later in the day, Anders Lennartsson, a spokesman for Ikea Food Services, said, "We take seriously the test result from the Czech Republic authorities, indicating presence of horse meat in one batch of our meatballs."
Results of DNA tests conducted by the food industry in Britain, released last week, showed that 1 percent of beef products were tainted with horse meat. But that news was offset by the discovery of tainted beef products destined for school meals in Scotland.
And, while the issue is primarily seen as one of fraud and mislabeling, there is concern that a powerful equine painkiller, phenylbutazone, or bute, may have entered the food chain.
"It started off as a local problem, then became national, then international," said Chris Elliott, the director of the Institute for Global Food Security at Queen's University Belfast. "At the last count, something like 19 countries were involved either in the supply chain or in uncovering tainted products."
Mr. Elliott highlighted the complexity of the supply chain for processed food as a big factor in the loss of quality control. Horse meat is significantly cheaper than beef, so unscrupulous individuals can profit from the substitution, he said.
"Wherever you have a high-value product and you can substitute it for a lower-value product, people will try to do so," he said. "that's the history of the food industry, unfortunately."
The evidence suggested that cases were widespread and included the substitution of pork for beef, as producers sought to lower costs.
The most likely solution is either an increase in DNA testing, which is expensive, or a simplification of the supply chain to enable better controls.
"Either way, there is going to be a substantial additional cost in food production," Mr. Elliott said.
Ikea's announcement came as European Union ministers gathered to discuss changes to a farm subsidy program, but their meeting was swamped by the meat crisis.
Desperate to restore consumer confidence, ministers at the meeting spoke in favor of extending European Union rules on food labeling. Since 2011, labels on unprocessed beef sold in Europe have been required to identify where a cow was born, raised and slaughtered; most countries now want this requirement extended to processed beef. This could prove cumbersome, as processed food contents often originate in multiple countries.
Tonio Borg, Europe's commissioner for health and consumer policy, told the news conference that place-of-origin labeling for processed foods would not have stopped those intent on fraudulently passing off horse as beef. "The problem is not an absence of regulations," he said.
He said that the European Commission, the union's policy-making arm, would accelerate a report on labeling issues that was originally due at the end of the year. Once the report is done it will take months for its findings to be turned into legislation.
Stephen Castle reported from London, and Andrew Higgins from Brussels.
This article originally appeared in The New York Times.