U.S. officials on Wednesday sued J.C. Penney, accusing the retailer of deceiving consumers by advertising textile fiber products as containing bamboo and bamboo fiber, when they actually contain rayon.

According to a complaint filed by the Department of Justice and Federal Trade Commission, J.C. Penney (JCP) in “numerous instances” deceptively advertised products such as men’s socks, pillow shams, and bath rugs as containing bamboo.

But the government said that under the federal Textile Fiber Products Identification Act, the products actually contained and should have been marketed as containing rayon.

J.C. Penney received a FTC warning letter in February 2010 about the marketing of textile fiber products, yet advertised its products incorrectly following that receipt, the complaint said.

“Consumers have suffered and will continue to suffer substantial injury as a result of defendant’s violations,” the complaint said.

The lawsuit was filed in the federal court in Washington, D.C. It seeks civil penalties and a halt to further violations.

J.C. Penney did not immediately respond to a request for comment. The Justice Department and FTC did not immediately respond to similar requests.