melamine leopard
The new species in the Sunderbans is similar to a black leopard

A species of black leopard unknown to science has been captured on film in the Sunderbans, a vast tract of mangrove forest covering eastern India and Bangladesh.

According to a report in the Times of India, camera traps set to capture film of Bengal tigers instead provided evidence of an altogether new species - a never-before-seen big cat related to the black leopard.

The animal has been described as being a small black cat with a long tail and is unknown to zoologists.

The new species is bigger than a wild cat but smaller than the more familiar spotted leopard. Officials said it could be a melanistic leopard-cat, which is black all over, but say it is more likely to be an entirely new species.

The Sunderbans is the only tiger reserve in India where no leopards have ever been spotted.

"We have never seen any animal like this in the Sunderbans," said Sunderbans Biosphere Reserve director Pradeep Vyas.

"Apart from 18 tigers, scores of other cats, including jungle and fishing cats, were found during the exercise, which was done outside the reserve area for the first time.

"Most of them were expected till we came upon two sightings of a black cat with a long tail."