The commission spent a month conducting more than 4,000 DNA tests on beef products throughout the European Union, and the results of the study – published on Tuesday – found that French beef has been worst-affected by the horsemeat scandal among European nations.

A total 13.3 percent of the 353 tests carried out in France showed traces of horse, followed by Greece at 12.5 percent, Latvia, with 10 percent, and Denmark with 9.1 percent.

The commission decided on the extensive testing on February 15th, as part of an effort to take control of a scandal which had spread throughout Europe since early 2013.

France was first rocked by the scandal in early February. Since then, several French food retailers have withdrawn whole ranges of pre-packaged or frozen ‘ready meals’, falsely labelled as beef, but actually containing horsemeat.

On February 14th a French government investigation concluded that the French company Spanghero had “knowingly sold horsemeat” – a claim which the company denies.

Further European Commission testing found no presence in French beef of phenylbutazone, the painkiller known as‘bute’ which is used on horses but can be harmful to humans.

Indeed, the study found only 16 cases of ‘bute’ contamination throughout the entire European Union – 14 in Great Britain, one in Ireland, and one in the Czech Republic.

A spokesman for the commission played down the risk associated with the painkiller, however.

“There is no immediate danger. You would have to eat hundreds of horse burgers for months to have problems,” Frederic Vincent told AFP.