Wal-Mart has issued a voluntary recall for all donkey meat products sold at various locations in China. The world’s largest retailer made the announcement after lab tests revealed the popular snack in certain areas of China was tainted with traces of fox DNA.

A representative from Wal-Mart has offered a reimbursement for anyone who purchased “Five Spice” donkey meat. China’s livestock industry yearbook confirmed the country slaughtered 2.4 million donkeys in 2011 alone, Reuters reported.

"We are deeply sorry for this whole affair," Walmart's China president and CEO, Greg Foran, said in a statement. "It is a deep lesson (for us) that we need to continue to increase investment in supplier management."

While the initial cause of the contamination has not been determined, Wal-Mart’s President and CEO in China, Greg Foran, has promised the company will boost its attention on “supplier management.” The Shandong Food and Drug Administration is launching an investigation into the “adulteration incident.”

The U.S. company based in Bentonville, Ark., is also launching its own investigation into the incident. Wal-Mart has promised legal action against the product retailer and has already detained a person in charge at the supplier factory.

Wal-Mart already operates 400 locations in China and plans to open an additional 110 new stores within the next couple of years. The company has already dealt with food safety issues in China after health officials in city of Nanning reported the use of expired eggs in baked good products.

"This is another hit on Wal-Mart's brand, meaning wealthy shoppers will start to lose the trust they had before," Shaun Rein, Shanghai-based managing director of China Market Research (CMR) Group, told The Wall Street Journal.