The news reports of horse DNA in products across Europe continue multiplying as testing turns up more positive results.

In Great Britain, horsemeat was found at Taco Bell restaurants in a product marketed as ground beef from cattle. In response, the U.S.-based company removed beef products from the menu in Britain and Spain. Swedish-based furniture chain Ikea pulled meatballs from stores across Europe after tests showed horsemeat DNA. Switzerland’s Nestlé removed pasta meals from the market in Italy and Spain after discovering horsemeat traces.

Additionally, Birds Eye, a British packaged-food company, found horse meat in two products in British markets. The products were manufactured by Frigilunch N.V., which also made a product sold in Belgium tainted with horsemeat.

The Food Standards Agency in Britain announced in a March 1 update that more than 99 percent of the 5,430 tests completed thus far show horsemeat levels below 1 percent. Above 1 percent distinguishes “between gross contamination or adulteration, and ‘trace’ levels of carry-over from one species or product to another.”

So far, the FSA has found 17 products from 11 companies to contain at or above 1 percent horsemeat. None of those products were contaminated with phenylbutazone (bute), which threatens humans if consumed.

Testing has begun to help trace the source of the meat, although the exact chain and extent of the contamination is yet unknown. Ikea traced meatballs tainted with horsemeat to a Swedish supplier that had contracted with two Polish slaughterhouses, reported The Local.

U.S. officials told USA Today that it’s unlikely horsemeat could slip unnoticed into food in the United States due to extensive U.S. Department of Agriculture inspection of meat upon importation, as well as bans on selling horsemeat for human consumption in the country.