BujangBujang the nine-year-old orang-utan stares dejectedly through the bars of his tiny cage, the last survivor of his breed in a horror Borneo zoo.

Eight other orang-utans have died there in the last seven years from ill-health – mostly tuberculosis – according to conservationists, leaving Bujang to live in misery against the shrieks of laughter from tourists enjoying the surrounding theme park.

His diet and the stress of looking out at the surrounding forest where he should be playing is so bad that he is now losing the hair on his back – and animal lovers fear he too could die unless he is rehabilitated.

But Bujang is not the only animal in the zoo at the Sinka Island Park in West Kalimantan, the Indonesian side of Borneo island – a visiting team of conservationists were moved to tears at the plight of Cika the elephant, chained up for 24 hours, seven days a week.

And there are horses, their rib cages showing through lack of food and nourishment.

‘This cruelty to the orang-utan, the elephant, the horses and many other animals such as a lonely baby sun bear in a tiny cage must end immediately,’ Mr Gunning Gea, director of Scorpion Wildlife Trade Monitoring Group, insists.

‘Quite simply, either these poor suffering animals have to receive immediate treatment, improved living conditions – or they have to be removed from there. This cannot go on.

‘This zoo should be ordered to stop the cruelty that we have seen.

‘The option is to move the orang-utan to a better place, to a rescue centre, and be given the chance to live in a wild habitat.’

Mr Upreshpal Singh, director of the Malaysian-based Friends of the Orangu-tans, who visited the zoo recently, admitted he was moved to tears at the plight of Bujang and Cika the elephant.

‘These are nightmarish conditions. It’s a daily hell for them. This zoo needs to be shut down and all animals relocated,’ he tells me.

‘I have to say that the treatment of Cika, who is about 12 years old, and nine-year-old Bujang is eye-watering.

‘I took photos of her chained up. She can hardly move. She is suffering severe stress and urgently needs to be saved.’

The zoo, part of the Sinka Island Park located some five miles from the regional capital of Singkawang, is privately owned and while Chinese-Indonesian proprietor was not available for comment a keeper told the visiting conservationists: ‘What’s the problem? They (the animals) are all OK. No problem.’

But animal lovers insist there is a major problem.

‘In 2009 there were at least nine orang-untans at the zoo,’ said Mr Singh. ‘Another conservationist recently informed Nature Alert UK that all but one – Bujang – died from tuberculosis and poor care.’