WASHINGTON (AFP) - Walmart said Wednesday it will tighten inspections on its suppliers in China after it was forced to recall donkey meat products that had been found to contain fox.

The US company, the world's largest retailer, said it would also change its rules in China to ensure that meat shipments are properly documented before they hit the shelves.

On January 2, Walmart recalled donkey meat from some Chinese stores after tests found traces of other animals' DNA. It promised independent tests all of its "high risk" meats in China.

The recall came after the Shandong Food and Drug Administration said that Walmart's "Five Spice Donkey Meat" product contains fox.

Walmart said it had invested in a computer-based system across the supply chain to allow vendors to upload all required legal documents in its compliance process.

The requirements include providing a product label that accurately reflects the product ingredients, laboratory test reports on food items and manufacturer permits.

Vendors must also verify claims that a product is "organic" or has health benefits, the Bentonville, Arkansas-based retailer said.

Shares in Dow component Wal-Mart Stores were down 0.3 per cent at US$74.42 in midday trade on the New York Stock Exchange.