LONDON — Taco Bell, a business unit of Yum! Brands, Inc., is the latest food company to become embroiled in the scandal of products labeled as 100% beef, but containing levels of horse meat above 1%. Taco Bell said the tainted product came from a European company, but did not identify the supplier.

“We immediately withdrew ground beef from sale in our restaurants, discontinued purchase of that meat, and contacted the Food Standards Agency with this information,” the company said in a statement. “We would like to apologize 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.”

Taco Bell’s presence in the United Kingdom is small. The company only has three outlets.

The Food Standards Agency released the updated results of its testing program on March 1. The agency said to date 5,430 tests have been completed and 44 have tested positive for horse D.N.A. above the 1% threshold. There are 310 tests still in progress.

“As in previous weeks, the vast majority, over 99%, of tests continue to show no horse D.N.A. at or above the level of 1%,” the F.S.A. said. “There are now 17 products confirmed as containing over 1% of horse D.N.A., which have been identified through the industry tests. A further two products have been identified through separate tests.”

The F.S.A.’s testing program only includes companies in the U.K. Horse D.N.A. has been found in other countries in Europe, including Italy, Germany and the Czech Republic.