They are the adorable, furry little creatures with the big round eyes who almost purr in delight as they are tickled into a stupor. They are also an endangered species whose stardom on YouTube is fuelling a trade built on cruelty and abuse.

The slow loris, a species of primate native to South-east Asia, rivals Justin Bieber as a viral internet sensation. A video of an animal being tickled has gained more than six million views. A new clip, posted this month, in which a loris clutches a cocktail umbrella, has been viewed two million times.

The creature's new-found fame is now stoking demand among children to turn the wild animal into must-have living toys. But the primate is no pet.

Poachers steal infant lorises from their parents in the wild to sell at open-air markets in Indonesia, where they are traded for as little as £10.

The export market is most lucrative in Japan, where lorises stolen to order sell for £3,500. The trade is now expanding into the US and Europe, with illegally smuggled lorises reported in the United Kingdom.

But many do not survive the journey. "The only reason the loris isn't biting the person holding it in the video is because it has had its teeth ripped out with pliers," said Chris Shepherd of Traffic Southeast Asia, which campaigns against the trade in primates.

The teeth are removed because the loris, listed as vulnerable to extinction by the International Union for Conservation of Nature, can deliver a toxic bite. Mr Shepherd said: "The creature is then effectively doomed because of infection. Most don't last very long after that."

Dr Anna Nekaris, reader in primate conservation at Oxford Brookes University, said there is also a "massive" trade in Poland and Russia. "I have visited markets in Thailand where they advise on how to smuggle them into Britain," she adds.

Dr Nekaris said the loris in the umbrella video had suffered a head wound, most likely caused by being transported in a cage. Although the creature may look happy, it submits to being tickled as a passive defence-mechanism to deal with stress.

The loris is a nocturnal animal and is effectively being blinded by the daylight in the videos. Disoriented, it grasps at the umbrella believing it is the bamboo of its natural terrain.

Unable to fend for themselves if they survive, lorises can't be returned to the wild once caught. Ripped from their parents, who would clean the infants, their skin becomes covered in urine and faeces.

Dr Nekaris is now calling on YouTube to take down the loris clips, which conservationists believe promote an illegal trade. Mr Shepherd said: "Lorises are still traded openly in Indonesian markets and the YouTube clips only increase the demand. Tackling this trade should be an urgent priority for wildlife-enforcement agencies. The penalty should be greater than simply confiscation of the animal."

A spokesman for YouTube said: "All videos uploaded must comply with our Community Guidelines, which prohibit animal abuse.