Investigators responded to a request for assistance delivered by the U.S. Drug Enforcement Administration, the Xinhua News Agency reported.

"We will find out the truth as soon as possible and if there are illegal activities, we will handle them according to the law," Yan Jiangying, a spokeswoman for the State Food and Drug Administration, or SFDA, said Saturday.

U.S. authorities said last week they had arrested more than 120 people and uncovered dozens of steroid labs in an international investigation into the illicit trade of performance-enhancing drugs, federal officials announced Monday.

The DEA said the investigation, dubbed Operation Raw Deal, was assisted by governments of China and eight other countries.

China provided assistance in bringing indictments against a Chinese corporation and its chief executive on charges of smuggling illegal human growth hormone into the country in connection with the operation, the DEA said.

In Connecticut, four men were charged with purchasing raw steroid powder from China, manufacturing anabolic steroids in home laboratories and distributed them to customers through a MySpace.com profile and a Web site.

Yan said China would share information with its U.S. counterparts and "jointly fight against illegal production, sale and use of steroids." Xinhua said Chinese regulations require licenses to produce and sell steroids.

China, long dogged by a series of doping scandals involving its athletes, has won praise from America and WADA, the international anti-doping agency, for cooperating with the steroid investigation.

WADA chief Dick Pound last week said China, the host of next year's Summer Olympic Games, said China was "in active cooperation with the various international agencies that are involved."

"It's pretty early in the process to know exactly what all the information may be, but I think they are equally committed to doing something whatever is appropriate if they find there are illegal activities here in China," Pound told reporters during a visit to Beijing.

The United States has stepped-up anti-drug cooperation with China in recent years, opening a DEA office in Beijing, and sharing resources as international drug gangs seek to exploit new Asian markets and expand their global distribution chains.

In march 2006, Chinese and U.S. agents seized more than 314 pounds of cocaine smuggled from Colombia.