LONDON — The United Kingdom’s Food Standards Agency has published the results of its first set of industry tests of beef products for the presence of horse meat. Out of 2,501 samples, 99% came back negative for the presence of horse DNA. Twenty-nine samples tested positive, but the F.S.A. said the samples were related to products that already had been reported and were in the process of being removed from the market.

The F.S.A. also said the testing is not complete and that there are 950 samples that are still in progress. Testing laboratories in the U.K. have been overwhelmed by the demand for testing services.

‘It’s encouraging that we have received so many results from industry so quickly, which reaffirms their commitment to working with us to address the serious issue of consumer confidence in the U.K. food supply,” said Catherine Brown, chief executive officer of the F.S.A. “More important for consumers, it shows that in the vast majority of cases the results so far are showing that no horse DNA is present in the foods tested. But this is still far from the full picture and we expect industry to continue to supply us with regular updates on their testing regime.”

On Feb. 14, police in the U.K. arrested three men in relation to the horse meat fraud. Two of the men work at Farmbox Meats while the other works for the Peter Boddy Slaughterhouse. Both companies were closed by the F.S.A. earlier this week after tests revealed horse meat blended with products sold as beef.

The F.S.A. also announced that Rangeland Foods, a company based out of Ireland, had initiated a recall of beef burgers after finding products contaminated with between 5% to 30% horse meat. The affected products were distributed in the U.K. to caterers and wholesalers.

The scandal has raised consumer concerns about the quality of the U.K. food supply and on Feb.  15, the chief executives of 11 food retailers and processors published an open letter to the public in an effort to reassure them.

“The food industry is determined to restore consumer confidence in the food we sell as quickly as possible,” the letter said. “We can't accept a situation where the trust customers place in us is being compromised by fraudulent activity or even as alleged, an international criminal conspiracy.

“That is why we are acting together with the Government and the Food Standards Agency, not only to get to the bottom of how this has happened but to take whatever steps are necessary to reassure customers that they can trust the food they buy.”