The French and British governments have vowed to punish those found responsible for allowing horsemeat originating from Romania to be sold as beef.
The British unit of frozen foods group Findus began recalling its beef lasagne last week on advice from its French supplier, Comigel, which said the questionable meat came from Romania.
"From all the data we have at the moment, there is no breach of European rules committed by companies from Romania or on Romanian territory," Prime Minister Victor Ponta told a news conference. "I am very angry, to be honest."
An initial French investigation revealed that the horsemeat ended up in Comigel's Luxembourg factory, supplied by a French firm, and that a Dutch and Cypriot trader had also been involved. However, the meat originally came from a Romanian abattoir.
Romania exports €10-12 million of horse meat a year, the Ziarul Financiar daily said, quoting agriculture ministry data, and authorities had investigated two unnamed abattoirs to check on their possible involvement.
"It is very clear that the French company did not have any direct contract with the Romanian company and ... it has to be established where the fraud was committed and who is responsible for this fraud," Ponta said.
Horse and carts remain a common means of transport in the Romanian countryside and some can even be seen on the edges of major cities, including the capital Bucharest. When horses are too old for work, farmers often sell them to abattoirs.