Pressed by conservationists to shut down breeding farms housing some 5,000 tigers, China hinted Tuesday it may abandon a proposal to legalise domestic trade in furs and tiger-bone medicine.

A document drafted by Beijing, to be submitted for approval to the UN body regulating wildlife trade, said nations that breed the endangered species "on a commercial scale should implement measures to restrict the captive population to a level supportive only to conserving wild tigers."

The language is significant, says conservationists, because it may signal a reversal of China's position, and because it removes any possible justification for maintaining large populations of genetically-compromised tigers that cannot be released into the wild.

"The managed, coordinated zoo population of tigers is in the hundreds, which is enough to maintain genetic diversity," said Kristin Nowell, an expert on illegal tiger trade at wildlife monitoring network TRAFFIC, one of dozens of conservation and wildlife groups sharply critical of the farms.

Three other tiger-range nations co-authored the document -- India, Russia and Nepal -- but China is the only one to allow large-scale husbandry of the critically endangered big cat.

The plight of tigers is one of the two most emotive and highly charged issues, along with African elephants, to come before the 171-nation Convention on International Trade in Endangered Species, meeting for the first time in three years.

"It seems to us that China gets the message," said Nowell. "The document is fine. Now we will have to see how well it is implemented -- we will be watching."

Coming into the meeting, China had floated the idea of opening its domestic markets to a series of tiger-based products, arguing it would boost local economies and serve conservation goals too.

"The growing of artificially-bred tiger populations would not only constitute a steady foundation for the potential re-opening of utilization of tiger bones and furs," China said in an official CITES document, "but would also provide an abundant breeding stock for future re-introduction and restoration of the wild tiger populations in China."

Conservationists, however, say the mass-bred tigers would not survive in the wild and suffer the consequences of intense inbreeding.

China allows the farms, at least one of which is government-run according to TRAFFIC, despite a CITES ban on international trade as well as domestic rules outlawing commerce in tiger parts or pelts.

Beijing claims that the farms are only used as tourist attractions, but investigations by CITES and non-governmental organizations have found evidence of illicit trade.

DNA tests, for example, showing that meat served at a restaurant near the Guilin Xiongsen Tigers and Bears Mountain Village in Guangxi province came from a tiger "appeared to be valid," CITES enforcement officer John Sellars said Tuesday.

The tests, ordered by the Independent Television News team that collected the meat during an investigation, was submitted to the US Fish and Wildlife Service's national forensics lab for verification, Sellars said.

CITES has asked the Chinese government to open an investigation, he added.

One of two farms in China with at least 1,000 tiger specimens, the Guilin operation produced large quantities of "bone-strengthening wine" made from tiger parts before the national ban in 1993.

The owner, Zhou Weisen, told investigators that he had stopped production of tiger-based elixirs, using captive-bred lions instead. But allegations that tigers are still used in medicinal preparations have persisted.

Experts estimate that only a few thousand of the majestic carnivores remain in the wild, mainly in India.

The species is almost extinct in China, with as few as 20 specimens still roaming in the tropical southwest or along the border with Siberia.