US-based restaurant chain Taco Bell, which has three sites in the UK, has confirmed that some samples of its ground beef have tested positive for horse meat.
The finding was revealed by the Food Standards Agency (FSA) following a third round of testing of beef products across the country, amid fears of horse meat contamination.
In a statement on its website, Taco Bell, which has sites in Lakeside shopping centre in Essex, Eastgate shopping centre in Essex, and Manchester's Arndale centre said: "Food quality is our highest priority, and when the news of mislabelled beef products surfaced we voluntarily carried out tests on the ground beef supplied to our three Taco Bell restaurants in the UK.
"Based on that testing, we were very disappointed to learn that some batches of ground beef supplied to us from one supplier in Europe tested positive for horsemeat.
"We immediately withdrew ground beef from sale in our restaurants, discontinued purchase of that meat, and contacted the Food Standards Agency with this information.
"We would like to apologise to all of our customers, and we can reassure you that we are working hard to ensure that every precaution is being undertaken to guarantee that we are only supplied with products that meet the high standards we demand."
The FSA said that to date it has now received 5,430 test results, including 1,797 published today. As in previous weeks, 99% of tests showed no horse DNA at or above a level of 1%.
However four further products, including those of Taco Bell, did test positive. There have now been 17 products testing positive for more than 1% of horse DNA since tests began.
To date, no tests of products containing horse DNA have found the veterinary medicine phenylbutazone (bute).