A federal grand jury has indicted two Chinese nationals and the businesses they operate, as well as a U.S. firm and its CEO, for their roles in importing contaminated wheat gluten used in the manufacturing of pet food in the U.S. The contamination led to a nationwide recall of certain pet foods from companies like Menu Foods and Procter & Gamble, and is believed to have sickened thousands of animals, killing as many as 16. In March 2007, the U.S. Food and Drug Administration (FDA) announced that testing of certain Menu Foods pet food had revealed the presence of a chemical used in the production of plastics. The chemical, called "melamine", was also found in testing of wheat gluten that was used as an ingredient in the affected pet food products. The New York Times reports that yesterday's indictment -- filed in Kansas City, the port of entry for the contaminated wheat gluten -- cites e-mails sent between the Chinese manufacturer and the American importer as proof that the tainted ingredient was intentionally mislabeled to avoid inspection.