Horse meat scandal hits kebab shops: why did it happen?

Sarah Coles
the slaughterhouse
the slaughterhouse

They have long been the but of jokes about the quality and identity of their meat, but now kebab shops and other takeaway stores have been dragged into the horse meat scandal.

It turns out that they may have received 100% horse meat - labelled as beef or lamb - from a UK slaughterhouse and meat factory. But why is this happening?