Indonesia's last sub-species of tiger - the Sumatran - is doomed unless the trade in its body parts is stopped and its habitats saved, campaigners warn.
Demand for body parts is widespread
One estimate suggests there may be only 400-500 of the tigers left in the wild.
A new report says demand for medicinal ingredients, trophies, charms and souvenirs in Asia is driving a systematic programme of killing by hunters.
The concern is raised by Traffic, the wildlife monitoring network, and WWF, the global conservation organisation.
Traffic's undercover investigators found what they described as a substantial domestic Indonesian market for tiger parts.
The investigators found animal products in 17 of the 24 towns they visited. About 20% of 453 shops they went to had body parts on sale, mostly teeth and claws. Much of this trade is done in the open, says Traffic, even though it is illegal.
The campaign groups argue this trade is unsustainable. They claim there is evidence to show that at least 50 Sumatran tigers have been poached per year between 1998 and 2002.
"It is a catastrophic level of poaching," Stuart Chapman, from WWF, told the BBC.
"The population simply can't sustain this level of killing. There is no chance of this population being re-populated from somewhere else - it is an island population. The prognosis is not good."
Their forest habitat is under pressure
"Increased and improved enforcement is the only thing that is going to save the Sumatran tigers," said Chris Shepherd, a co-author of the Traffic-WWF report.
"As a first step, action should be taken against the markets, trade hubs and retail outlets highlighted in the report, especially in northern Sumatra. More specialised anti-poaching units also need to be established urgently."
The report, called Nowhere To Hide: The Trade In Sumatran Tigers, also shows how the trade in Sumatran tiger parts extends to South Korea, Taiwan, Singapore, Japan, Malaysia and China.
The Sumatran tiger is listed as Critically Endangered, the highest category of threat. The fear is that it will go the same way as two other tiger subspecies, the Bali and Javan tigers, which became extinct in the 1930s and 1980s respectively.
Loss of forest habitat is another major threat to the Sumatran tiger. The remaining animals are being pushed back by logging companies which exploit Indonesia's lowland rainforests to supply the world with paper pulp.
Traffic and WWF want the paper companies to agree to a moratorium on their logging operations in natural forest, some of which is prime tiger habitat, until the conservation value of the forests can be assessed.
The tigers may be being pushed into a conflict with humans
The Asia Pulp & Paper (APP) company, one of the biggest in the region, said it "deplored the killing of any endangered species" and claimed it had set aside 77,000 hectares (190,200 acres) of land for conservation in Sumatra.
APP says it has a plan in place to make its activities fully sustainable in 2007 and has accused WWF of being "extreme" in its dealings with the company.
Loss of habitat has also been blamed for bringing villagers into conflict with the animals. Eight people have been mauled to death by tigers in Sumatra since August 2002.
"The Sumatran tiger is one of those iconic species," said Sarah Christie, a tiger expert with the Zoological Society of London (ZSL).
"If we save it we pass the test because in protecting its habitat we will save so many other species from extinction as well."
Christie is a member of the Jambi tiger project - a partnership of the ZSL, an oil palm company, PT Asiatic Persada, and the Indonesian Government - which is tagging the Sumatran tigers with radio collars to learn more about their conservation needs.