An intimate story of hands-on environmental activism and a revelation of the true extent of Rodrigo Duterte's war on drugs intersect in Karl Malakunas' documentary Delikado, which has just had its world premiere at Hot Docs. Set on the paradisiac island of Palawan, the film follows three heroes as they fight to defend the land and rainforests from illegal logging, fishing and the destructive expansion of tourism sanctioned by the Filipino government.

Bobby Chen is an environmental lawyer and head of the Palawan NGO Network Inc (PNNI). The organisation ventures into the forests and goes after the loggers, confiscating their chainsaws, or does likewise with the boats of illegal fishermen who fish with banned chemicals. Following the opening, thriller-like scene that could easily have come straight out of a guerrilla war film, we see that the organisation's headquarters is a veritable museum containing 700 chainsaws alongside several boats and machines. A lanky, long-haired, devoted Christian, Chen comes across as both shrewd and honest, with the air of a seasoned fighter who pushes on against all odds because he truly believes in the cause.

Efren "Tata" Balladeres is the head of operations at PNNI. He used to be a logger himself, when he was part of the government's paramilitary force created to repress communist and Muslim terrorism, and ostensibly protect the rainforests. But when they were handed chainsaws, he made a U-turn and considers his activism penance for these sins.

Finally, Nieves Rosento is the mayor of Palawan's most touristic town of El Nido, and she has been working closely with PNNI and has gained popularity among the local communities. Now up for re-election, standing against a candidate from autocratic governor Jose Alvarez's and Duterte's party, she is accused of being a narco cartel member. Once again faced with the Filipino dictator using his war on drugs as a smokescreen to intimidate rivals and strengthen his grip on social and economic levers, Rosento is forced to look for protection.

Delikado tells its story in the tried-and-tested manner of an investigative documentary, with several candid scenes showing PNNI land defenders in action in the rainforests and on the coast. The loggers and fishermen they apprehend are not the real villains; rather, they are just poor people with no other opportunities to make a living. The true exploiters of the land beyond Alvarez and Duterte are never named. In contrast, we get very close to the heroes, including an activist who gets killed in one such action, in a segment with immense emotional power.

The Philippines is the most dangerous country in the world for land defenders, says a report from Global Witness. Similarly to stories about the struggles of local communities in the Amazon or DR Congo against greedy governments and corporations, the documentary has an intense feeling of urgency and immediacy. However, it also intimately introduces us to the indigenous tribes, so that even the sequences that would be treated as B-rolls in a TV report, such as wide shots of the islands, the aerial shots of the growing network of roads snaking through the forests, or an atmospheric image of a fishing boat against the sunset, gain essence as we come to understand the deep connection between the locals and their land. It is not just property; their way of life literally hinges on their environment.

Delikado is a co-production between US companies Thoughtful Robot, ITVS and American Documentary | POV, and Narravi Films from Australia, in association with the UK's Doc Society Climate Story Unit.