LONDON -- Taco Bell is the latest restaurant chain to acknowledge that its food has been adulterated with horse meat, yanking a variety of ground beef products from its three British outlets and issuing an apology to its patrons Friday.

Meanwhile, in Iceland, a food official said his team had found a beef product from a local producer that contained no meat at all.

Chief meat inspector Kjartan Hreinsson said a brand of beef pie found at a Reykjavik supermarket had "no mammalian DNA."

"That was the peculiar thing," he said. "It was labeled as beef pie, so it should be beef pie."

It should be, but across Europe meat labeled as beef has been found to be contaminated with horse -- from frozen food at supermarkets to fast food in restaurants and even school and hospital meals.

Authorities say the fraudulent labeling poses no health risk, but the scandal has drawn attention to the complex supply chains behind processed meat products.

Thousands of products have been tested, and found that contamination is relatively rare. Britain's Food Standards Agency said Friday that of more than 5,400 products tested in Britain, more than 99 per cent were clear of horse. Still, a steady drumbeat of brands found to contain horse meat has kept the issue in the headlines. Taco Bell joins a long list of food providers -- Nestle, Burger King, Tesco, Birds Eye, Findus and even Ikea -- that have had to remove products amid horse meat revelations.

British authorities said Friday that horse DNA had also been found in Birds Eye spaghetti Bolognese and beef lasagna and spicy minced beef skewers from catering company Brakes, which supplies pubs and the House of Commons Food Service.

In a statement, Taco Bell owner Yum Brands Inc. said: "We apologize to our customers and take this matter very seriously as food quality is our highest priority."

The company's presence in Britain is tiny compared to its profile in the United States, where it has more than 5,600 restaurants. Taco Bell stressed that its U.S. restaurants do not use meat from Europe and are not affected.

Yum Brands' statement gave no further detail as to the nature of the supplier, and the company said it would not reveal the information as the matter was being investigated by Britain's Food Standards Agency. A spokesman could not immediately say how long the supplier had been providing food to Taco Bell, or how many customers were thought to have been affected.

Burger King was hit by the horse meat scandal last month when it withdrew patties from an Irish supplier whose products were found to contain horse.

McDonald's said Friday that samples of all its burgers sold in Britain had been tested and none contained horse meat.

As for the Icelandic non-meat pies, Hreinsson said they appeared to have been stuffed with some sort of vegetable matter. He said the municipal authorities are investigating.