'It's a risky job,' says Hardi, who has had to send his family into hiding because he thinks he's in so much danger. In his time he's been beaten up and sent death threats. Those who want him silenced include the organised criminals running the international trade in wildlife species - which sells anything from rare cockatoos to apes. These wild animals are sold as pets or dismembered and made into bizarre Far Eastern medicines.
He's also fighting Indonesia's multi-billion dollar palm oil industry. Each year the country loses millions of hectares of primeval forest. Hardi believes that in order to rescue orangutans, he must save their habitat. He says, 'I want to help every orangutan in trouble but if we just rescue and rescue it's an endless job - we have to stop the deforestation itself'.
The team's Centre for Orangutan Protection (COP) runs a campaign against some of the large organisations that Hardi says are responsible for the catastrophic destruction of rain forests in the orangutans' main habitat of Borneo. The forest is being destroyed to make way for plantations producing palm oil. Some companies claim it is a tool in the fight against the use of fossil fuels that cause global warming - because it can be used as a bio-fuel. But environmentalists say that's just 'greenwashing'. Palm oil is used mainly in the food industry. Borneo also has vast deposits of coal, which is mined from open pits for exports to China. Indonesia is the world's largest producer of palm oil - and one of the biggest exporters of coal too.
The COP team zooms about Borneo's back roads in an orange off-road vehicle they call the 'Ape Crusader' - rescuing infant orangutans fleeing the devastation. Unreported World filmed COP's work, which seemed to repeat a pattern that was by turns full of redemption but also the grim reality that even now the battle to save both the forest and the species that live in it is being lost.
What we saw on our Unreported World shoot was horrific. Forestry is scythed down, bulldozed and burned until the land becomes a muddy desert to be replanted with palm. Orangutans and other species flee this Armageddon into dwindling patches of forest or farmers' land. Adult orangutans on the orders of some plantation farmers are killed, a reward is offered on delivery of an adult orangutan's hands or skull.
Orangutan babies sometimes survive, to be turned into pets kept in captivity by local people or sold into the international wildlife trade. The babies we filmed Hardi and his team saving were like survivors in a refugee camp. They were starving and diseased, on the brink of death with pot bellies and stick-like limbs. COP saves hundreds of infants like this each year, aiming to return them to the wild - what there is left of it.
Fewer than 50,000 orangutans still survive in the wild, and their populations are in steep decline. The orangutan is a flagship species, a symbol of the forest where it once thrived, but countless other species are also on the brink of extinction. It is only a few people like Hardi and his colleagues at COP that stand in the way of the total destruction of Indonesia's fabulous environment.