The internet has emerged as one of the greatest threats to rare species, fuelling the illegal wildlife trade and making it easier to buy everything from live lion cubs to wine made from tiger bones, conservationists said today.

The internet's impact was made clear at the meeting of the 175-nation Convention on International Trade in Endangered Species (Cites).

Delegates voted overwhelmingly today to ban the trade of the Kaiser's spotted newt, which the World Wildlife Fund says has been devastated by internet trade.

A proposal from the US and Sweden to regulate the trade in red coral – which is crafted into expensive jewellery and sold extensively on the web – was defeated. Delegates voted the idea down mostly over concerns that increased regulations might damage poor fishing communities.

Trade on the internet poses one of the biggest challenges facing Cites, said Paul Todd, a campaign manager for the International Fund for Animal Welfare.

"The internet is becoming the dominant factor overall in the global trade in protected species," he said. "There will come a time when country to country trade of large shipments between big buyers and big sellers in different countries is a thing of the past."

The Ifaw has carried out several surveys of illegal trade on the internet and found that thousands of species are sold on auction sites, classified ads and chatrooms, mostly in the US but also Europe, China, Russia and Australia.

Most of the illegal trade is in African ivory but the group has also found exotic birds along with rare products such as tiger-bone wine and pelts from protected species like polar bears and leopards.

A separate 2009 survey by the group Campaign Against Cruelty to Animals targeted the internet trade in Ecuador, finding offers to sell live capuchin monkeys, lion cubs and ocelots.

"As the internet knows no borders, it causes several new problems regarding the enforcement of the protection of endangered species," the group said in its report.

The newt is a textbook example of what can happen to one species through trade on the web. According to a study by the WWF, the black and brown salamander with white spots is coveted in the pet trade. Now numbering only around 1,000, about 200 annually have been traded over several years, mostly through a website that was operated in the Ukraine.

"The internet itself isn't the threat, but it's another way to market the product," said Ernie Cooper, who spearhead the investigation into the newt for 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 the global market, you can find buyers." The red and pink coral, of which there are 32 species, is harvested in Mediterranean waters and turned into expensive jewellery in Italy, Taiwan and China, according to the marine conservation group SeaWeb. It is the most widely traded and valuable of all precious corals but has no international protection, resulting in a brisk international trade in the species, the group claims.

Opposition to the proposal was led by Japan, which also rallied its supporters last week to defeat an attempt to ban the international export of Atlantic bluefin tuna, a key ingredient in sushi.

They were joined by several coastal states including Indonesia, Malaysia and Iceland, all of whom argued the corals are crucial to the survival of local communities and are not over-harvested.

Meanwhile, delegates approved a voluntary conservation plan for endangered tigers that calls for tougher legislation in countries home to the big cats to tackle widespread smuggling and boost money spent on law enforcement.

The British plan also calls for countries to better control tiger farms – China has the most – and to phase out traditional medicine markets which fuel demand for tiger parts.

The proposal includes no funding for the 13 tiger-range countries, only a request for donor assistance.

Tiger numbers have plummeted because of human encroachment, the loss of nine-tenths of their habitat and poaching to supply the illegal trade. Their numbers have fallen from 100,000 at the beginning of the 20th century to around 3,600 today.