A new species of legless amphibian resembling a giant earthworm or a snake has been discovered in a remote but threatened area of Cambodian rainforest, conservationists said on Friday.

The grey-brown creature -- Ichthyophis cardamomensis -- was found in Cambodia's southwest Cardamom Mountains, an area under threat from habitat loss, according to Fauna and Flora International (FFI).

The new species is often mistaken for a snake, with larger species known to grow up to 1.5 metres (nearly five feet) in length, FFI said.

It was confirmed by scientists earlier this month according to leading Cambodian FFI herpetologist Neang Thy.

"These discoveries are important to demonstrate that much of Cambodia's biodiversity remains unknown and unstudied by science, and many more areas need to be searched," Thy, who has been researching amphibians and reptiles since 2003, told AFP.

The creature is caecilian -- an order of amphibians that look like snakes or earthworms and are generally found underground.

Once a stronghold of the toppled Khmer Rouge regime, the bio-diverse Cardamom Mountains are home to an array of rare species, including the Asian elephant, but the area faces widespread deforestation.

Conservationists warn that illegal logging and other habitat destruction could mean new species become extinct shortly after discovery.