Upon ordering a burger in a fast food chain, diners might have already come to terms with the fact there is a very slim chance of horse meat lurking under that tomato.
But the additions of rat and human DNA could be harder to swallow.
A new study from US-based food testing company Clear Labs has discovered, from a sample of 258 burgers, two cases of meat in vegetarian products, three burgers with rat DNA and one case of human DNA.
