It took more than 60 hours’ ferrying by road as well as boat and then an epic trek on foot to ensure the captive apes could again enjoy life in the wilds of West Borneo.

Each of the orangutans had found themselves needing the efforts of British-based charity International Animal Rescue and kindly villagers after suffering at the hands of humans.

Laksmi, a three year old female ape, was discovered languishing in a cage after being abandoned by a man fleeing police.

Teenage ape Pinoh, also a female, had been kept as a pet before being handed over to the authorities.

For Abun, a 25-year-old male, being captured last month meant protection from villagers angry over the way he was taking sanctuary in their community garden in the quest food, after he had been exiled from his own native forest by land clearance.

Footage shot by IAR conservationists show the efforts made to return the animals back to the rainforest as they joined forces with forestry department officials and locals to haul the apes to the Bukit Baka Bukit Raya National Park.

While Abun had spent only a month in quarantine at IAR’s rehabilitation centre in Ketapang after being rescued by the charity’s conflict response team, for both Pinoh and Laksmi captivity had meant six years of being prepared for survival in the wild.

Laksmi was as young as three when she was rescued; Pinoh was around seven.

It was only after both apes had mastered the skills of climbing, feeding and nest building at forest school, followed by a period of behaviour assessment, was the all-clear given for their return to the trees.

The final stages of the release operation were still an endurance challenge with the apes being carried by road and boat before the most arduous part of the journey could start.

Twelve porters took over the final task of carrying the apes’ special transport crates, weighing more than 300lb.

Karmele Sanchez, IAR programme director in Indonesia, said: “We are very grateful to the local villagers for helping us carry the cages to the release site.

“They have walked six miles up steep hillsides and across rivers carrying the very heavy cages. I don’t know what we would do without them.”

After travelling for more than 57 hours, the team reached the site where Abun could be released and, as soon as the crate door was lifted, he clambered up the tallest tree and began eating.

For the two young females, there were still a further five hours’ walking before they reached their release point in darkness.

Uray Iskandar, from the BKSDA forestry department, said: “The most uplifting thing is to see an orangutan returning to their natural habitat. The orangutan species is native to Indonesia and we must work to protect it and to protect its habitat.”

IAR monitoring teams will continue to follow and observe the orangutans around the clock to ensure they are safe and healty following their release, bringing the total number of apes released in the national park to 17 since 2015. Abun was the fifth wild ape to be returned.

Bukit Baka Bukit Raya National Park was chosen as the release site after IAR surveys showed it still contains plenty of fruit trees for the orangutans.