China has been unfairly branded a centre of fake drugs, an official with the country's drug watchdog said Tuesday, blaming instead some overseas companies that source their raw materials through illegal suppliers.

China's pharmaceutical industry is lucrative but poorly regulated. Chinese manufacturers and other players along the drug supply chain have been blamed in recent years for deaths linked to counterfeit or shoddy medications at home and abroad.

"The problem lies in the fact that some overseas companies have an implicit deal with underground factories or illegal manufacturers in China, so the product involved has problems," Bian Zhenjia, director of the drug safety supervision department under the State Food and Drug Administration, told a press conference Tuesday.

He did not name companies, but urged foreign companies to be more responsible and to source from legitimate suppliers.

Contamination in U.S.

Chinese suppliers were blamed last year for the deadly contamination of the blood thinner heparin, which was recalled in the United States after reports of deaths and hundreds of allergic reactions. As many as 81 died. Some heparin products were also recalled in Canada last year.

Raw heparin is derived from pig intestines, often processed by small, unregistered businesses in China.

China has also recalled drugs and herbal medicines on the domestic market. Counterfeit versions of popular drugs, such as Pfizer Inc.'s Viagra, are widely available.

A diabetes drug was pulled in January after it was linked to two deaths in the far western region of Xinjiang. Samples showed the medicine contained six times the normal amount of a chemical ingredient used to lower blood sugar.

China's SFDA counted 329,613 cases of distribution of unlicensed drugs and medical products in 2007, according to the China Daily newspaper.