Two Chinese businesses and a U.S. company were indicted Wednesday in the tainted pet food incidents that killed dozens of animals last year and raised worries about products made in China.

Xuzhou Anying Biologic Technology Development Co., Suzhou Textiles, Silk, Light Industrial Products, Arts and Crafts I/E Co., and Las Vegas-based Chemnutra Inc. were charged in two separate but related indictments.

The U.S. attorney's office in Kansas City said the tainted food led to the death and serious illness of pets in the U.S. last year.

One of the indictments charges Xuzhou Anying Biologic, located in China's Jiangsu Province, and Suzhou Textiles, in Suzhou, China, with 13 counts of introduction of adulterated food into interstate commerce and 13 counts of introduction of misbranded food into interstate commerce.

ChemNutra and company owners Sally Quing Miller, 31, a Chinese national, and her husband, Stephen S. Miller, 55, were charged with 13 counts of introduction of adulterated food into interstate commerce, 13 counts of introduction of misbranded food into interstate commerce and one count of conspiracy to commit wire fraud.

Steve Stern, a spokesman for ChemNutra, said the Millers "deny the allegations by the Justice Department in the strongest of terms and look forward to the opportunity to prove their innocence at trial. Neither Mr. nor Mrs. Miller had any intent to defraud or knowledge of any wrongdoing."

The indictments allege that Suzhou Textiles, an export broker, mislabeled 800 metric tons of wheat gluten tainted with the toxic chemical melamine to avoid inspection in China. Xuzhou then did not properly declare the contaminated product it shipped to the U.S. as a material to be used in food, the indictment says.

It also says the shipment was falsely declared to the Chinese government in a way that would avoid a mandatory inspection of the company's plants.

According to the indictment, ChemNutra picked up the melamine-tainted product at a port of entry in Kansas City, then sold it to makers of various brands of pet foods.

The indictment alleges that the melamine was added to make the gluten meet the required standard for protein content specified in the contract between Suzhou and ChemNutra.

"Millions of pet owners remember the anxiety of last year's pet food recall. These indictments are the product of an investigation that began in the wake of that recall," U.S. Attorney John Wood said in a news release announcing the indictments.

The indictment also names Xuzhou Anying Biologic owner and manager, Mao Linzhun, and Suzhou Textiles' President Chen Zhen Hao.