YUM Brands (YUM.NYSE) said on Monday that the food supply for its 450 Little Sheep hot pot restaurants were not affected by a recent scandal where rat meat was passed off as lamb, Reuters reported. According to reports, a Shanghai-based crime ring had passed off US$1 million (RMB6.1 million) in rat and small rodent meat as mutton. A spokesperson for the company said there was no evidence of any adulterated product in Yum’s food supply chain. One Shanghai-based supplier under investigation had invoices indicating that it had sold meat to the Little Sheep chain, The Wall Street Journal reported. YUM has struggled with a downturn in sales during the first quarter as a bird flu scare turned customers off eating KFC, its most popular brand.