The US-based global Yum Brands business, parent company of KFC, Pizza Hut and Taco Bell, has issued a profit warning after watching its sales in China drop.

A Chinese tv investigation about Yum’s chicken suppliers has proved controversial, and consumer sales have fallen, according to Inside Retail.

Yum is the major foreign fast-food chain in China with KFC’s 5,700-strong outlets making it the dominant brand.