A female orangutan was shaved, chained up and forced into sexual acts with men twice her size after being stolen as a baby, according to environmental workers.

The traumatised animal, known as Pony, is believed to have been chained up and repeatedly abused at a brothel in Kareng Pangi village, in Indonesian Borneo, for around six years.

“It was horrifying,” Michelle Desilets, director of Borneo Orangutan Survival Foundation, told The Sun. “She was a sex slave - it was grotesque. She was covered in abscesses, and they put make-up and earrings on her.

“She must have been in so much pain. It was horrible to think about how terrified she must have been.”

Men working at a nearby palm oil farm would pay the equivalent of “a couple of quid” to have sex with the primate, the newspaper reports. She was forced to wear jewellery, and was shaved every other day, which caused her skin to become irritated and infected.

Pony is one of many orangutans illegally traded throughout Asia. The apes are sold for up to £10,000 on the black market and even on social media sites.

Charity boss Desilets told the Daily Mirror that rescuing Pony had been difficult, because of resistance from local people in the village where she was held.

“Pony was a cash cow and she earned that village a lot of money. The whole village was not willing to let her go. They wanted people coming in - in this case, men from the fields - and spending their money,” she explained.

Pony was finally rescued in 2003 and now lives with seven other orangutans at Borneo’s Nyaru Menteng Rehabilitation Centre.

Orangutans were once found across Southeast Asia but today are confined to rainforests on the islands of Borneo and Sumatra. The future of the remaining primate population in the wild is at threat from widespread deforestation as a result of palm oil farming.

Earlier this year, a Christmas TV advert for superstore chain Iceland that depicted a baby orangutan’s forest home being destroyed was banned for being too political. Iceland was the first major UK supermarket to pledge not to use palm oil in its own-brand products.