British supermarket managers are rushing to pull burgers from their shelves.  

Why you ask?  Seems frozen patties from a company called Tesco was tested and came back with horse DNA.  The U.K. Telegraph reports that experts from the Food Safety Authority of Ireland were the whistle blowers on the whole incident.

Tests confirmed 30% of the meat contained horse meat, and after extensive testing all over Ireland, results came back with over a third of the company's products testing positive for horse DNA.

Meanwhile 85% of the patties tested contained meat from pigs as well.  Representatives from Tesco told the U.K. Telegraph, "The presence of illegal meat is extremely serious," and continued to say that the company would conduct their own investigation into the matter.