A type of diet pill is being blamed for at least one death in southern China. Officials in China and Hong Kong say some Chinese supplements claiming to help users lose weight may contain illegal amounts of amphetamines.

The diet supplement Yuzhitang is touted as a quick way to a slim figure. But health experts in China revealed recently that the weight-loss pills contain fenfluramine, a substance that experts in the United States have linked to certain health problems.

Although fenfluramine is banned in China, some diet products containing the substance are still found in pharmacies in the country, and, until recently, were sold in Singapore, Hong Kong and Japan.

C.T. Leung is a chief chemist at Hong Kong's government laboratory. He says some of the pills found their way onto shelves in Hong Kong because they come under the category of Chinese herbal medicine, even though many contain other chemical compounds. "We found that those claiming to be Chinese medicine, they are adulterated," he said. "It means that some Western drugs are added, the amphetamine types of drugs that affect the central nervous system. If Western drugs are added it becomes illegal."

Weight-loss pills from China have been suspected in at least two other deaths this year. One, called Slim-10, was linked to a Singapore woman's death from liver failure. Chemists there say the pills contained fenfluramine and other chemicals.

In Japan, one woman died and 11 others suffered liver disorders, allegedly after taking Chinese diet supplements. Japanese health officials are still working on identifying the substances in the product, which they say was labeled as an herbal diet aid. It is not yet clear if the pills were from the same manufacturer in China.

News media in China reported that the maker of the pills was investigated in January, and the products were ordered off the shelves in April. The action came after the death of a woman in the southern Guangdong province. Authorities only recently confiscated the business permits from the manufacturer.