The world’s only known albino orangutan has been released back into the jungle more than a year after she was found emaciated and bloody in a remote corner of Borneo, an Indonesian NGO said Friday.

Environmentalists rescued "Alba" from a cage where she was being kept as a pet by villagers in Central Kalimantan in April last year.

She was found with dry blood smeared around her nose -- the result of her violent capture -- and weighed just 8 kilogrammes, the Borneo Orangutan Survival Foundation (BOSF) said.

The blue-eyed primate, covered in fuzzy white hair, returned to the wild with her best friend, Kika, after more than a year in a rehabilitation centre Handout, Borneo Orangutan Survival Foundation/AFP

The blue-eyed primate, covered in fuzzy white hair, was on Wednesday returned to the wild with her best friend, Kika, after leaving their rehabilitation centre.

"So far she's showing good signs of adapting," Nico Hermanu, a BOSF spokesman, told AFP.

"She's been climbing trees as high as 35 metres (about 115 feet) and has been eating fruit from the forest."

Kika and Alba -- who is six years old and now 28 kilos -- will be monitored by conservation teams at Bukit Baka Bukit Raya National Park.

Environmentalists found 'Alba' with dry blood smeared around her nose - the result of her violent capture - and she weighed just 8 kilogrammes Handout, Borneo Orangutan Survival Foundation/AFP

The rescue is a rare spot of bright news for the critically endangered species, which has seen its habitat shrink drastically over the past few decades largely due to the destruction of forests for logging, paper, palm oil and mining.

The population of orangutans in Borneo has plummeted from about 288,500 in 1973 to about 100,000 today, according to the International Union for Conservation of Nature.

A string of fatal attacks on the great apes this year have been blamed on farmers and hunters.

Four Indonesian men were arrested over the killing of an orangutan shot some 130 times with an air rifle in February.

The rescue is a rare spot of bright news for the critically endangered species, which has seen its habitat shrink drastically over the past few decades largely due to the destruction of forests Handout, Borneo Orangutan Survival Foundation/AFP

Borneo police have also arrested two rubber plantation workers and accused them of shooting an orangutan multiple times before decapitating it.

Plantation workers and villagers are sometimes known to attack the animal because they see it as a pest, while poachers also capture them to sell as pets.