Laboratory results have revealed that the deaths of five rare Sumatran rhinoceroses at a breeding centre were caused by a bacteria present only in an unclean environment, a report said today.

The rhinos, which died within two weeks of each other, were suffering from colisepticaemia, which is linked to E.coli, the New Straits Times said.

The bacteria are only present in unclean environments and visitors to the centre noted that the animals were fed off the same floor they defecated on and that general hygiene was poor, the paper reported.

Killer bacteria

Animals which could have been carriers of the killer bacteria, including cockroaches, monkeys and rats also frequented the centre, it said.

The Sumatran rhinoceros is the smallest of the five types of rhino and one of the world's rarest large mammals.

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 Sungai Dusun Sumatran Rhinoceros Conservation Centre in Selangor state, where the animals died, had failed to achieve any rhino births in more than a decade. - AFP