The first photographs of the critically-endangered Vietnamese rhinoceros have been obtained by the World Wide Fund for Nature (WWF).

Scientists believe there are no more than eight of the rhinos still surviving, and possibly as few as five.

They have never seen a single specimen, and rely on reports from local people who have occasionally glimpsed the very shy creatures in the bamboo forest or at a saltlick.

They are so elusive that some scientists believed them to be extinct in Vietnam until 1988, when a hunter was arrested trying to sell a horn and a skin.

Most of what is known about the rhinos comes from study of tracks, droppings, and from people living in the area where they are, the Cat Tien national park, about 150 kms north of Ho Chi Minh City.

Hopes of finding more

The park director, Mr Tran Van Mui, has worked there for four years, and has seen only hoof prints and droppings.

"This is one of the most exciting events in the natural history of Vietnam", he said.

"It may even prove that there are more than eight rhinos surviving in the area."

The tiny band of survivors in Vietnam is a sub-species of the Java rhino, known also as the lesser one-horned-rhino.

The rhinos' self-portraits are short on detail

Between 50 and 60 animals of the other sub-species survive in Java itself, but cross-breeding between the two is thought to be impossible.

So far WWF has obtained seven pictures of the rhinos, taken in May by automatic cameras which are triggered when an object interrupts a laser beam.

The pictures are tantalisingly indistinct. One shows an animal with a small horn, a characteristic of female Javan rhinos.

But another, of an animal with mouth wide open, reveals large incisors, a characteristic of male Javans.

Although they live in a national park, the rhinos still face threats. Apart from hunting, they are losing their habitat as farmers convert more forest land into cashew nut plantations.