 In the European 2013 horse meat scandal, foods advertised as containing beef were found to contain undeclared or improperly declared horse meat—100 percent of the meat content, in some cases.A smaller number of products also contained other undeclared meats, such as pork.The issue came to light on January 15, 2013, when it was reported that equine DNA had been discovered in frozen beefburgers sold at several Irish and British supermarkets.