Frozen poultry products from Tyson Foods Inc., the world's largest meat processor, were found to be contaminated with salmonella, the General Administration of Quality Supervision, Inspection and Quarantine said on its Web site late Friday.
Other imports barred by China included frozen chicken feet from Sanderson Farms, Inc. tainted with residue of an anti-parasite drug, as well as frozen pork ribs from Cargill Meat Solutions Corp. containing a leanness-enhancing feed additive, the AQSIQ said.
A spokesman for Cargill denied the agency's claims, while officials at Tyson and Sanderson Farms were not immediately available to comment.
China's food and drug safety record has come under scrutiny in recent months following the deaths of cats and dogs in the United States and Canada blamed on tainted Chinese pet food ingredients. Worries at home and around the world have heightened as a growing number of Chinese products are found tainted with dangerous levels of toxins and chemicals.
Beijing has taken significant steps in recent days to clean up its product safety record, including executing the former head of its drug regulation agency for taking bribes and banning the use of a chemical found in antifreeze in the production of toothpaste.
Officials also have vowed to better integrate its fractured regulatory system, which splits responsibility among at least six agencies. The blurred lines often enable the country's countless illegal operations to escape detection.
The Chinese government has thoroughly investigated each case of substandard products, said Li Yuanping, director of the AQSIQ's import and export bureau, the official Xinhua News Agency reported Saturday.
"All of them are exceptional cases," he said, noting that more than 99 percent of China's exports meet standards.
"There is no such thing as zero risk. In term of food safety, it's impossible for any country to make 100 percent of their foodstuff safe," he said. "China-made products should not be labeled as substandard just because of a few bad producers."