All the major UK store chains, with the exception of Waitrose and Marks & Spencer, are embroiled in the OFT inquiry into milk prices in 2002 and 2003 which has been ongoing since the beginning of 2004. It was accepted by Asda, Sainsbury and Safeway that stores increased the price of milk as a result of collusion. Dairy Crest and Wiseman allegedly acted as middle men, passing on sensitive information about prices to their supposed rivals. Britain's biggest store chain Tesco, and Morrisons, are accused of collusion too, but vigorously deny they took part. The allegations against Tesco involve cheese as well as milk and butter.