Yum! Brands, the global operator of fast food chains comprising Taco Bell, Pizza Hut and KFC, has blamed the adverse publicity in China following a government imitated probe into one of its suppliers as the reason for faltering sales in the country.

Same-store sales for the company declined 6% year-on-year in the fourth quarter of 2012 against an estimated 4%, said the company in a filing before the US Securities and Exchange Commission.

Yum! attributed the more than expected decline to reports of excessive antibiotic residues in chicken supplied to the company.

Chinese supplier Shandong Liuhe’s eight chicken samples were found to contain excessive antibiotics, in tests conducted by independent third parties, raising fears amongst consumers.

Yum spokesman Jonathan Blum told Reuters that the Yum had stopped all supplies from Liuhe in August 2012 and has halted purchases from a problematic Yingtai plant.

"We certainly didn’t knowingly put any product into the marketplace that had excessive antibiotics.

"We feel comfortable that we have the very highest, industry-leading standards on food quality and food safety," Blum said.

Yum! operates over 5,100 restaurants in China and revenues from the country contributed 44% to its overall revenues in 2011.

Following a report by the Shanghai Food and Drug Administration, Yum! terminated the supplier’s contract but failed to contain the damage.