Beijing ? China said Friday it is investigating allegations that a Chinese company exported tainted wheat gluten used in pet food that has been linked to the deaths of more than a dozen cats and dogs in the United States.

It was the first time Chinese authorities officially responded to the uproar that has resulted in a ban on gluten imports from the Xuzhou Anying Biologic Technology Development Co. and a U.S. recall of nearly 100 brands of pet food.

“We are investigating this,” Zeng Xing, an official with the press office of the General Administration of Quality Supervision, Inspection and Quarantine, told The Associated Press.

Zeng, whose agency monitors the export of food, animals and farm products, refused to give any details of the probe other than to confirm China is looking into the claim that the exported wheat gluten contained melamine, a chemical found in plastics and pesticides.

Xia Wenjun, another agency official, was cited by the state-run Xinhua News Agency as saying that “sampling and examination” of wheat gluten was under way nationwide.

The probe will center on melamine, and officials will stay in touch with the U.S. Embassy in Beijing, Xia told Xinhua, adding that further measures would be taken “based on developments in the United States.”

According to state regulations, exported food should be inspected by Zeng’s agency. China’s customs service is supposed to allow a product to pass only when a certificate of quality supervision is provided.

It wasn’t immediately clear if those procedures were followed in the case of the wheat gluten, which is a protein-rich meat substitute developed in China and most commonly used in vegetarian and Asian cuisines.