If they do not want to take his word for it, the media can visit a bear farm to see for themselves, Fang said.

He did not clarify when a farm would open to the media, nor did he specify which farm would be opened.

"But it is not possible to completely open bear farms to the public because germs may pose potential risks to the bears kept for bile extraction if a large number of people pay a visit," Fang said.

In 2006, China had 68 registered bear farms where about 7,000 black bears were kept for bile extraction, statistics from the State Forestry Administration showed.

The number of bear farms increased to 98 by 2011, and it is estimated that about 20,000 black bears are kept for bile extraction, Animals Asia Foundation statistics showed.

Fang denied that the association has a "direct connection" to Guizhentang's IPO plan. But the company is listed as a member of the association, according to the association's website.

"Animal experts and veterinarians should also be allowed to enter the bear farms, if he wants to prove what he says," said Sun Quanhui, an official from the World Society for the Protection of Animals.

"I don't believe it at all that extracting bile is as easy and comfortable as Fang said. Why doesn't he extract the bile from his body in the same way to prove it?" wrote a female netizen from Chengdu, posting under the name Liangxiaotangtang on Sina Weibo, a popular micro-blogging site.

Bear bile is used in traditional medicine in China and other Asian countries because it is thought to have health benefits, such as detoxification, cleansing the liver and improving vision.

Years of research has shown that China can produce drug substitutes that have the same function as bear bile, said Jiang Qi, former vice-president of Shenyang Pharmaceutical University, in January.

But so far, government authorities have not approved the substitute drugs for sale on the market.