Researchers from the World Wide Fund For Nature (WWF) may have spotted a new mammalian species in the dense central forests of Borneo island, the organisation said.

The carnivorous animal, slightly larger than a domestic cat with dark red fur and a long bushy tail, was caught by a camera trap at night twice in 2003, the WWF said in a press release.

Photos of the animals have been shown to locals well acquainted with wildlife in the area and the organisation also consulted several Bornean wildlife experts but none recognized it.

"Most were convinced it was a new species of carnivore," WWF said, adding that researchers were hoping to set cage traps to catch a live specimen.

If confirmed, it would be the first time in more than a century that a new carnivore has been discovered on the island, it added.

The animal, which has very small ears and large hind legs, was spotted in the Kayan Mentarang national park in the mountainous jungles of Kalimantan, where vast tracks of rainforest still remain.

"The discovery of the mammal species in Kayan Mentarang national park indicates the existence of many other undiscovered species. Between 1994 and 2004, at least 361 new species have been described from Borneo," the WWF said.

The group warned however that plans by Indonesia announced in July to create the world's largest palm oil plantation in Kalimantan, along the border with Malaysia's Sarawak and Sabah states, threaten further new discoveries.

The scheme, funded by the China Development Bank, is expected to cover an area of 1.8 million hectares (4.4 million acres) -- about half the size of the Netherlands -- and may have devastating environmental consequences, it said.

Environmental watchdogs have criticized the plan, arguing that the jungle soil in the area was infertile and that the elevation was unsuitable for palm oil.

Indonesia is losing at least 2.8 million hectares of its forests every year to illegal logging alone.

Rapid deforestation has had devastating environmental consequences for both Indonesia and the Southeast Asian region, causing floods and landslides and shrouding nearby countries with haze from illegal fires set to clear land.