Three Sumatran white tigers mauled a Malaysian to death in Singapore's zoo on Thursday after the man, a cleaner, jumped into their enclosure, a zoo official said.

He suffered injuries to his neck and body, and died before the ambulance arrived at 12.45pm.

Nordin Bin Montong, 32, from Sarawak, leapt into the moat of the white tiger exhibit and was attacked, said Biswajit Guha, assistant director of zoology at the Singapore Zoo in a statement.

The Straits Times reported that he was not supposed to be in the tiger enclosure and was assigned to clean the chimpanzee section.

He was seen behaving in an agitated manner before he fell into the moat.

Mr Biswajit Guha told Reuters, "The police are still investigating it, we are not able to assert what exactly happened, but prior to the incident the keepers had actually noticed the contract worker behaving a bit erratically. He was throwing things around, as he was walking out of the zoo he was passing comments like, 'good-bye, you won't see me again.' He later cycled back in and about five minutes later, the alarm went off."

According to The Straits Times horrified visitors at the enclosure thought it was part of a show until one of the tigers bit Mr Nordin's back and started dragging him to the tigers' den.

They started screaming.

The noise from the attack caught the attention of zookeepers nearby and they eventually managed to distract two of the tigers but a third continued to maul him.

"Keepers managed to separate the worker from the tiger. While waiting for the ambulance, our vets attended to him," said Mr Guha. "The worker tragically succumbed to his wound."

The Singapore Zoo said the white tiger exhibit would be closed and investigations were ongoing after the midday attack.

"Our heartfelt condolences go to the worker's family and we will provide his family with whatever assistance they need during this period," said Mr Guha.

According to conservation group WWF, there are about 4,000 tigers left in the world and they are considered an endangered species.

White tigers are even rarer because they suffer from a genetic condition that strips their fur of the orange pigment,leaving the animal with snow white fur, black stripes and blue eyes.

(Additional reporting by Reuters and straitstimes.com)

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