He spent two years shut in a dark wooden box before he was finally rescued.
Kotap, a young four-year-old male orangutan, was found in a box measuring just 10 square feet (1 square metre) when rescuers in Indonesia got to him.
People from wildlife group, International Animal Rescue (IAR), and officials from the West Kalimantan forestry department discovered the animal trapped in a village, kept as a pet.
The man holding him, named Baco, claimed to have been given the orangutan by some people he met in his village, IAR said in a Facebook post.
When rescuers found him, Kotap had nothing but a straw and a plastic bottle with him.
He was fed a human diet that included uncooked instant noodles and sugary drinks.
Watch a video of the rescue here:
Baco said he was concerned that Kotap would disturb the neighbours, so he built the wooden cage for him in front of his house.
Officials had to visit Baco several times before being able to persuade him to surrender Kotap.
But it wasn’t easy to rescue the frightened monkey, even after obtaining permission.
“Kotap was very stressed by all the strangers who gathered to see him when he was taken out of the box,” said Uwi, a vet with the IAR.
“He became nervous and aggressive which is not surprising. So during the long journey back to the centre we kept people away from him so that he remained as quiet and calm as possible.”
Kotap will now be taken to join other rescued orangutans at the IAR’s rescue centre for treatment and rehabilitation.
“Kotap lived a sad and solitary existence, unable to exercise or behave in any way like a wild orangutan,” said Alan Knight, Chief Executive of the IAR.
“Thankfully now he will join other rescued orangutans at our centre and be given a chance of returning to the forest where he belongs.”