A rare salamander is being driven to the brink of extinction in the wild because of internet trading, conservationists say.

The little-known Kaiser's spotted newt, found only in Iran, is thought to be the first creature to face the threat of extinction from e-commerce – a growing threat to endangered wildlife which authorities are struggling to address. Because Neurergus kaiseri is very attractively coloured, and also rare, amphibian enthusiasts are willing to pay as much as £200 for one. Dealers can often only find people willing to pay such a price by advertising on the internet.

An investigation into the sale of Kaiser's spotted newts by the wildlife trade monitoring agency Traffic found 10 websites claiming to stock the species, including a Ukrainian company which said it had sold more than 200 wild-caught specimens in a year.

The demand has been such that the wild population, found only in four streams of Iran's Zagros Mountains, was reduced by 80 per cent between 2001 and 2005 alone, and is now classed as critically endangered. It is estimated that fewer than 1,000 mature individuals remain.

Conservationists want all international trade in wild-caught Kaiser's spotted newts made illegal. A proposal to ban such trade has been put forward by Iran at the conference of the Convention on International Trade in Endangered Species (Cites), in Doha in the Arabian gulf.

"The internet itself isn't the threat, but it's another way to market the product," said Ernie Cooper, of Traffic Canada. "The Kaiser's spotted newt, for example, is expensive and most people are not willing to pay $300 for a salamander. But through the power of the internet, tapping into global market, you can find buyers."

Kaiser's spotted newts were being advertised for sale on numerous websites yesterday, but the animals did not appear to be wild-caught. Babies were being offered for £40 each for delivery anywhere in Europe, with North American sellers asking for around twice that price including free next-day shipping. Some sellers claimed their salamanders had been captive-bred in 2008.

Illegal wildlife trade is gaining ground on the internet, according to Cites. Officials say that while wildlife law enforcement has made gains in policing physical markets for wildlife, the online world – with its "virtual" markets that have yet to be properly regulated – presents a set of new challenges.