Ilham was sitting outside on his terrace in the village of Kuala Langkat on April 18 when a scrum of men in plainclothes arrived at his home and strong-armed him into a waiting car.

Ilham’s younger brother said the men didn’t show any credentials, and that there was a scuffle as Ilham resisted.

“My brother was taken without any explanation by people who claimed to be police,” Nuzul told Mongabay Indonesia. “When asked where the arrest warrant was, they ignored it.”

Nuzul said the mangrove forest in Kuala Langkat village was part of a protected area that had remained in good condition until about 10 years ago. That was when a man identified only by the initials BP arrived in the area and claimed a concession covering 100 hectares (247 acres), which he began clearing to plant oil palms.

Over time, BP sold off parcels of the concession, around 3-5 hectares (7-12 acres) apiece; to date, he’s sold around 65 hectares (161 acres) to buyers.

A large share of the community objected to this destruction of the mangrove forest, and Ilham reported the deforestation to the provincial police headquarters in North Sumatra. He would later travel back several times to follow up on the case with police.

Frustrated by the lack of response, Ilham is alleged to have taken matters into his own hands by damaging a shelter in the protected forest used by workers hired to cut down the mangrove trees and replace them with oil palms. Ilham was reported to the police for alleged vandalism.

The Indonesian archipelago is home to 45 of the world’s 75 mangrove species, growing in some 3 million hectares (7.4 million acres) of mangrove forests, which is more than a fifth of global mangroves, according to Wetlands International. The trees provide crucial ecosystem services and serve as feeding grounds for the marine life that coastal communities rely on for protein needs.

In addition, mangrove trees store up to five times as much carbon in their biomass and soil than terrestrial forests, giving them an enhanced role in slowing climate change.

However, almost half of Indonesia’s mangroves have been damaged or destroyed in recent decades as the trees are ripped out to make way for aquaculture businesses and plantations.

In response to this environmental challenge, President Joko Widodo in 2020 announced a target to restore 600,000 hectares (nearly 1.5 million acres) of mangrove ecosystems by 2024.

Local people who spoke with Mongabay pointed out that authorities had been mostly unresponsive to Ilham’s pleas to act against the mangrove destruction, yet were swift and uncompromising in going after him for damaging property.

Dedi Mirza, the chief police investigator in Langkat district, where the village of Kuala Langkat is located, confirmed Ilham’s arrest on April 26, more than a week after he was detained. He said the arrest was made following a report of criminal damage and that Ilham faced charges that carry a maximum sentence of five and a half years in prison.

Dedi said an arrest warrant was produced within 24 hours after the arrest, and that the 40-year-old was charged following a review of photo and video evidence of the incident. Crucially, Dedi determined that the land in question didn’t have protected status, and that no law had been broken by the concession holder, BP.

Adi Yoga Kemit, a lawyer for Kontras, said their investigation had found villagers who opposed the destruction of mangrove forests faced threats and intimidation by thugs hired by the businessmen.

“We urge the police to arrest the financial backers and anyone involved in destroying mangrove forests in Kuala Langkat,” Adi said. “Stop criminalizing people who protect mangroves.”

Advocates from LBH Medan have twice visited the North Sumatra police headquarters to request information on the encroachment of Langkat’s mangrove forests.

“We urge that Ilham’s report regarding the damage to the mangrove ecosystem in Langkat be followed up immediately,” Adi said.