A new species of primate, a "big-eyed" and venomous slow loris, has been identified in Borneo by researchers.

But the new loris is already under threat from the Asian pet trade in part because its "teddy-bear face" make it attractive for illegal poaching, the team of UK and US scientists said.

Analysing the facial markings of slow loris in the Indonesia island, the researchers concluded that the nocturnal Nycticebus kayan is new to science, and two others that were previously considered sub-species should be recognised as unique species in their own right.

The lemur-like slow loris is found across south-east Asia, and is notable for having a toxic bite – a rarity among primates. But the species are listed as vulnerable or endangered by the gold-standard IUCN Red List of threatened wildlife.

Rachel Munds, a University of Missouri doctoral student who was one of the team who identified it, said: "Unfortunately, in addition to habitat loss to deforestation, there is a booming black market demand for the animals. They are sold as pets, used as props for tourist photos or dismembered for use in traditional Asian medicines."

She added that technological advances had enabled the team to identify it as a separate species. "Historically many species went unrecognised as they were falsely lumped together as one species. While the number of recognised primate species has doubled in the past 25 years some nocturnal species remain hidden to science."

The findings were published in the American Journal of Primatology.