Discovering a new species can be the defining moment of a biologist's career, but for some it can also mean exposing rare and vulnerable animals to the dark world of the wildlife pet trade, with catastrophic results.

It's a scientific dilemma that has led some conservationists to question whether it would be better to hide their findings from the world.

In 1999, herpetologist Bryan Stuart was working in Northern Laos when he stumbled across an eye-catching newt he had never seen before.

The creature was prehistoric in its appearance with thick, warty skin and bright, yellow dots all the way down its back.

He spotted it in a bottle of alcohol that a Lao colleague had brought back from a wedding in a remote part of the country - the poison from the newt's skin had been used to make a drink with special medicinal properties for a toast to the newlyweds.

Stuart went in search of the newt in the wild and three years later he published an article in the Journal of Herpetology, announcing the discovery of the new species, Laotriton laoensis.

Finding a customs officer anywhere in the world that cares much about newts is difficult Chris Shepherd, Traffic

"When you see one of these animals in the wild in your hand for the first time and you recognise that it is absolutely unique, it's like discovering a treasure," he says.

But his joy turned to horror when he realised his discovery had caught the attention of amphibian dealers around the world. Examples of the species were popping up in pictures on amphibian pet forums as far away as Germany and Japan.

Stuart soon realised that trading networks had emerged between Laos and the West and traders were using his report as a roadmap to capture and sell hordes of the newts.

"The mindset of these commercial collectors is to go in, get as many as you can, as quickly as you can, to make as much money as possible," he says.

Image caption Smugglers sold Laotriton laoensis newts for $200 each

"What's worse is they have set up these trade networks with local villagers telling them to collect as many as they can."

The Lao newt lives on the surface of rock pools and was easy to find. Villagers were typically offered less than $1 (£0.63) for each newt. Smugglers then sold them on to hobbyists for as much as $200 (£130).

Because the newt is unique to Laos and only found in three small areas in the north of the country, the population was quickly decimated.

In 2008, six years after the publication of Stuart's paper, a biologist from the National University of Laos, Somphouthone Phimmachak, proved the species was close to extinction. Her work led to the Lao newt being granted official status as a threatened species, making it illegal to trade specimens caught in the wild.

It wasn't the first time a scientific discovery has put a rare species in danger.

"A turtle from the small Indonesian island of Roti was so heavily hunted that today it is nearly extinct in the wild," says Stuart. A rare gecko from south-east China was removed from its natural habitat entirely by smugglers who got prices as high as $2,000 (£1,272) for each.

Why should we care about newts? "Amphibians are the new canaries in the coal mines," says Ariadne Angulo of the IUCN

They are often the first species to respond to pollution or change in climate and are crucial in surveys of landscape health

A third of all known species of known amphibians are classified as threatened

Amphibians eat a lot of invertebrates and are an important source of food for larger predators Source: Ariadne Angulo, IUCN

Jason Lee Brown, a herpetologist who has studied poison frogs in Peru since 2003, describes three separate incidents where his discoveries put a species' existence under threat.

In 2006 he published the picture of a new species of poison frog, Ranitomeya benedicta on the internet. Almost immediately it appeared in trade shows in Europe and North America.

Two years later it happened again when he published the description of a second new species and again when he reported the rediscovery of a third species thought to be extinct.

In 2010 Brown returned to the area in Peru where he had initially discovered R. benedicta and found that locals had been cutting down canopies in the trees where the frogs were known to live.

"I almost quit what I was doing," he says.

Two of these frogs were declared threatened last year.

Endangered species status is meted out by the International Union for Conservation of Nature (IUCN), according to the convention on trade in endangered species (Cites). It was first signed in 1973 and has now been ratified by 175 countries.

But according to some conservationists, endangered species status creates new problems. Chris Shepherd of Traffic, an organisation that monitors the wildlife trade, believes the endangered label can boost animals' black market value.

Image caption This illegal shipment of frogs were on their way to Europe from Peru when they were found dead

He regularly visits the wildlife markets of Jatinegara in Jakarta and Chatuchak in Bangkok where he has seen traders advertising the fact - albeit slyly - that the animals they sell are endangered and illegal.

Traffic is working to train local law enforcement agencies to clamp down on illegal wildlife trade. But obliterating wildlife trade is low on the political agenda in countries such as Laos, Indonesia, Thailand and Peru.

"Customs have a very important role to play being at the front line of import and export," says Shepherd. "But finding a customs officer anywhere in the world that cares much about newts is difficult."

Relying on governments in developing countries to address the issue is pointless, agrees Jason Lee Brown, who got little help from the Peruvian authorities when he drew cases of frog smuggling to their attention.

Smuggling is a drop in the bucket Mark Pepper, Frog conservationist

"There is widespread apathy, they have so many issues to deal with that are more important and they just don't have the infrastructure to deal with this," he says.

He believes the responsibility lies with those in the developed world who are driving the pet market.

Peruvian hunters, many of whom live on $1.25 (£0.79) a day, can get about $2 (£1.30) a frog. Collectors in Europe and the US will pay up to $1,000 (£636) a pair, making smuggling a very lucrative business.

Some people believe the only viable solution to the trade of wild animals is captive breeding.

Mark Pepper, who has worked with Brown on frog conservation projects in Peru, runs a legal and ethical frog breeding business but sometimes he finds illegal traders selling species he has never worked with under his name.

He thinks smuggling is not the most pressing threat to amphibians. For some species, such as the Lao newt, smuggling can have a devastating effect, but most amphibians face the much greater threat of habitat destruction.

Timber felling and mining are a much greater risk to the frogs he has studied in Peru, he says.

"Smuggling is a drop in the bucket."

The logical thing it seems would be to keep the locations of the animals secret and some scientists do choose to do this.

Last year theNew York Times reportedthat a herpetologist in Malaysia, Indraneil Das rediscovered a striking amphibian called the Borneo rainbow toad previously thought to be extinct. Das avoided publishing its specific location.

Similarly, after his experience with the Lao newt, Bryan Stuart discovered a species of poison snake and decided to keep its location secret. But it was something he was uncomfortable doing.

He believes that scientists need to share knowledge of which species occurs where so that they can co-operate with each other and the public to preserve the species and its habitat.