China's drug watchdog promised to investigate how alleged counterfeit pills, which were made in China, ended up being used by the British National Health Service (NHS).

"We will conduct relevant investigations and will surely punish companies or individuals who manufacture fake pharmaceuticals for export", Yan Jiangying, spokeswoman with State Food and Drug Administration (SFDA) said on Wednesday.

"If we find any clues of illegal medicine production for export, we will track them down," the spokeswoman told Xinhua in an exclusive interview.

A London-based newspaper, The Guardian, said on its website Jan. 4 that "counterfeiting gangs based in China" produced some eight million fake pills which went to NHS patients last year.

Chinese police authorities recently traveled to London to discuss the growing problem, The Guardian said.

The information, however, cannot be confirmed at this time.

Yan reiterated China's resolution to crack-down on importing or exporting fake medicines. She emphasized that the government adopted international principles and practices to regulate the issue.

According to Chinese laws, medicine exporters should acquire government-issued certificates to run their business. Exported pills should be accompanied by permission papers for sales in accordance with requirements of the World Health Organization (WHO).

The spokeswoman said foreign pharmaceutical traders should cooperate with certified Chinese partners to ensure qualified and safe medicines.

"The government not only pays attention to the domestic market, but also closely cooperates with the WHO and other countries to curb fake pills," Yan said.