Efforts to save from extinction one of the world's rarest large mammals, the Sumatran rhinoceros, have been dealt a "tragic" blow by the mysterious deaths of all five animals in a local breeding programme, conservationists said today.

"The fifth Sumatran rhinoceros has died. We just don't know the cause. We are going to do a post-mortem to find out what caused the deaths," a wildlife officer told AFP on condition of anonymity.

A rhino named Mas Merah died Monday after more than two weeks fighting an unknown disease which had already claimed the lives of its four companions at the Sungai Dusun Sumatran Rhinoceros Conservation Centre in Selangor the past two weeks.

Only about 300 of the animals are left worldwide, mainly in Malaysia and Indonesia, their numbers having been slashed to a dangerously low level by poaching and the destruction of habitat.

The Sumatran rhinoceros, the smallest of the five types of rhino, has already been wiped out in Cambodia, Laos and Thailand, said Chris Shepherd, an official with the conservation group Traffic Southeast Asia. There are just some 70 left in peninsula Malaysia.

Rhino horn

The government has vowed to continue with its breeding efforts despite the loss but Shepherd told AFP it should instead concentrate on protecting the animal in the wild.

"What happened in Malaysia is tragic. I understand the motive behind captive breeding in Malaysia. Captive breeding has saved a number of species.

"(But) protecting rhinos in the wild should be the highest priority, rather than taking them out of it, especially if you house them in one place, making them vulnerable to a virus or bacteria," he said.

Shepherd, who described the Sumatran rhino was one of the world's rarest large mammals, said there was a big demand in Southeast Asia for rhino horn and skin to treat fever and other ailments.

Prior to the deaths of the five rhinos, two others had died at the breeding centre - Shah of renal failure in 2002 and Rima due to old age early 2003.

In more than a decade, the conservation center had failed to achieve any rhino births.

"We have been very unlucky. We had successful mating but no pregnancies. We had experts from the US and Africa to share expertise but no results," a rhino expert with the wildlife department told AFP .

Programme to continue

Mohamad Khan Momin, Malaysian Rhino Foundation chairman, said wildlife authorities planned to obtain more wild rhinos for the programme.

"I believe very strongly that the programme must continue . We are trying very hard to prevent the species from going extinct.

"Once a substantial number of young rhinos have been bred, we can reintroduce them into the wild," he was quoted as saying by the New Straits Times newspaper today.

But Khan said the programme must continue at an entirely new facility.

"In fact, we want to have two new facilities, so if something like this happens again, we can move them out quickly. There is no point catching more rhinos and sending them to certain death," he said. - AFP