The conservation group said American scientists compared the DNA of the clouded leopard with that of its mainland cousin and determined the two populations diverged some 1.4 million years ago.

"Genetic research results clearly indicate that the clouded leopard of Borneo should be considered a separate species," WWF quoted Dr. Stephen O'Brien of the U.S. National Cancer Institute, which carried out the tests, as saying.

The clouded leopard is Borneo's largest predator, has the longest canine teeth relative to its size of any cat, and can grow as large as a small panther.

There are estimated to be between 5,000 and 11,000 of these animals left in Borneo's rain forests, which are threatened by logging and are believed to hold many more undiscovered species, WWF said.