Vietnam has been one of Southeast Asia's most biodiverse countries, but some species may be lost before they are known to science due to an illegal global trade believed to be trailing only drugs and gunrunning.
Two new reports spell out that, despite Vietnam's international commitments to combat the trade, the smuggling of tigers, monkeys, snakes, pangolins and other animals to and through Vietnam is booming.
"Vietnam's illegal trade in wildlife continues unabated and affects neighbouring countries," wrote Nguyen Van Song of the Hanoi Agricultural University in the Journal of Environment and Development.
"Wildlife in Vietnam has become very scarce."
The study estimated that up to 4,000 tonnes of live animals or meat, skins, ground bones and other illegal products are trafficked into and out of Vietnam per year, generating more than 67 million dollars in revenues.
Species are mostly sourced from Vietnam's national parks and neighbouring Laos and Cambodia, to be consumed in Vietnam, China, South Korea, Taiwan and Japan, according to the study based on hundreds of interviews.
The largest volume of illegal wildlife goods is smuggled across the Vietnam-China border, with an estimated 2,500 to 3,500 kilogrammes (5,500 to 7,700 pounds) flowing daily through the two major border gates, it said.
There have been high-profile crackdowns. In a case last week, Vietnamese police seized more than two tonnes of live snakes and 770 kilogrammes of tortoises from Laos en route to China.
But the report estimated that the total value of confiscated wildlife accounts for only three percent of the illegal trade, and that authorities are at a disadvantage when a forest ranger polices an average of 1,400 hectares (3,500 acres) of forest at a monthly wage of about 50 dollars.
Smugglers connected to "influential people" -- shorthand for gangsters -- bribe or threaten officials and hide their contraband in trucks, ambulances, wedding and funeral cars and prison vans, the report said.
The capital Hanoi is Vietnam's largest market for illegal wildlife meat, with revenues of over 12,000 dollars a day, the report said.
"Hanoi is the cultural and political centre of Vietnam where wildlife protection and conservation policies are issued and implemented," said the report.
"This suggests that the gap between policies and implementation of wildlife protection is still big."
The most popular species served in Hanoi were snakes, palm civets, monitor lizards, porcupines, leopards, pangolins, monkeys, forest pigs, hardshell turtles, soft-shell turtles, civets, boas and birds.
The other market fuelling the trade is traditional Vietnamese and Chinese medicine, said a report by the wildlife monitoring network TRAFFIC.
Surveys found that "many high-profile animals of global conservation concern (such as tigers, bears or rhinos) can still be bought on the market, provided prior notice is given and that the price negotiated is high enough."
Informants had told TRAFFIC that live tiger cubs, tiger skeletons, raw materials and processed medicinal products were brought from Cambodia, Laos and as far as Malaysia to supply the Vietnamese market.
Traders in Ninh Hiep commune near Hanoi had offered to supply investigators with "any type of medicinal animal if ordered sufficiently in advance" -- including a frozen tiger, rhino horn and wild bear gall bladder.
The shop-owners who offered the illicit goods, the TRAFFIC report found, were "well organised, each claiming that they were shielded from investigations through protection by enforcement personnel."