Federal agents arrested a 30-year-old Chinese national in Hawaii for allegedly manufacturing and importing counterfeit weight-loss pills that contain dangerous levels of a restricted drug.

Sengyang Zhou of Kunming, Yunnan, China, appeared before a U.S. magistrate judge in Honolulu and now faces prosecution in Colorado, according to U.S. Immigration and Customs Enforcement.

He is charged with drug offenses that carry up to a 38-year prison term and fines of up to $1 million.

Zhou allegedly sold fake diet pills over the Internet, including versions of the brand-name drug Alli, made by Glaxo-Smith Klein.

One of Zhou's customers developed heart attack symptoms after taking the pills, which contained the drug Sibutramine, an appetite suppressant used to treat obesity, officials said.

The FDA has warned the public about counterfeit versions of Alli, an over-the-counter weight-loss drug, because of dangerous levels of Sibutramine, which is only available legally by prescription and can cause high blood pressure, seizures, palpitations, heart attack or stroke.

Zhou traveled from China to Hawaii to meet with individuals interested in distributing the pills in the U.S. and was arrested Tuesday without incident by agents of ICE, the FDA and the U.S. Postal Inspection Service, a news release said.

Since 2008 the FDA has issued alerts of tainted weight-loss pills and counterfeit drugs, including Super Slim, 2 Day Diet and Meizitang. The drugs were believed to have been imported from China and marketed as diet supplements or nutritional products.

Agents also arrested Qing Ming Hu, 60, a Chinese-born U.S. citizen living in Plano, Texas, who allegedly operated a U.S. branch of Zhou's company.

During the investigation, agents identified Zhou as the alleged drug trafficker and the manufacturer of the counterfeit version of Alli.

Zhou sold products through a Web site called http://www.2daydietshopping.com, officials said. He also placed postings on business-to-business Web sites that solicited orders from customers in the U.S. and abroad, communicating with potential customers via Yahoo! e-mail accounts, according to the investigative agencies.

Undercover agents placed orders for the counterfeit pills, which led to his arrest.