Animal mass grave discovered at Chinese zoo

The discovery comes just weeks after more than a dozen tigers were found to have died of starvation at another Chinese zoo amid suggestions that the administrators wanted to harvest their parts to make expensive – and banned – tiger-bone tonic.

The bones and remains of a quantity of animals could be seen poking through the snow In a three-metre deep pit near the Harbin Northern Forest Zoo, in Heilongjiang province in northeast China, state media reported.

They included two white tigers, five white lions, two leopards and five other big cats that had died in early 2008, zoo staff told a Chinese reporter.

Also believed to be buried in the mass grave were two of the zoo's three Asian elephants and 28 of its 29 endangered great bustards.

Zoo officials said the deaths followed a decision in 2007 to change the animals' diet to save money when the zoo ran into financial difficulties. A regimen of mutton and beef was replaced with chicken. Some keepers even gave their lions corn buns instead of meat.

Zhang Xinru, deputy head of the feeding department of the zoo, said that the animals showed no differences in the first month and a half of the new diet.

After six months the zoo noted a sharp fall in their body weight and after the deaths of 14 big cats in 2008 officials returned to feeding them beef and mutton. However, the animals were still suffering from malnutrition after a poor diet for such a long period.

Another zoo employee said that more than 80 per cent of the animals were being fed on bean cakes to keep up their protein levels. However, the zoo could no longer afford cakes of sufficient quality.

The employee said: "The animals eat this feed every day and many can only just stay alive. Death is coming closer and closer."

The zoo was so short of funds that rare golden monkeys – one of China's most treasured animals – were being fed only three types of fruit instead of the six varieties they should be given and the quality was very poor.

A senior zoo official said the bodies had been buried in the pit because the zoo could not afford to build an incinerator. The grave was regularly disinfected and the animals had died naturally of illness or old age, officials said.

Earlier this month a zoo in northeastern Shenyang was closed after 13 endangered Siberian tigers starved to death. Some newspapers said the animals may have been used to produce valuable tiger-bone liquor, much prized in China as a tonic to boost virility.

Additional support for that report came from a Chinese journalist who went undercover at the Harbin Siberian Tiger Park, where more than 1,000 of the animals have been bred in captivity, to investigate whether tiger-bone tonic was being sold illegally.

The journalist said he was offered tonic containing tiger bone at 2,800 yuan (£280) a bottle or without bone parts at 780 yuan (£78) a bottle. When he asked a zoo employee if the tonic was fake, he received the answer: "Why would we bother to sell fake tonic?"