Indonesian police were accused by a rights group on Tuesday of opening fire on a protest in Borneo against an oil palm company last week, killing one demonstrator and injuring at least one other.

Rights groups have long criticised police in the archipelago nation for heavy-handed tactics against demonstrations opposed to government policy or economic projects accused of harming the environment and Indigenous rights.

Three rights groups said police opened fire on residents of Seruyan village in Borneo's Central Kalimantan province Saturday as they protested a palm oil firm not giving up 20 percent of its concession land under government law.

They allegedly killed 35-year-old man Gijik, who like many Indonesians goes by one name.

"Police committed violence by shooting teargas, and then shooting two people. One died, who was shot in his chest," said Uli Arta Siagian, forestry and plantation campaigner at the Indonesian Forum for the Environment (WALHI).

The rights group said at least 20 people were detained. Local media reported they have all since been released.

The government scheme known in Indonesia as "plasma" orders that certain palm oil firms must give a fifth of their concession land to smallholders.

"WALHI demands the government to resolve the main issue, namely the agrarian conflict. The people's demand must be fulfilled by the corporation," said Siagian.

Palm oil firm PT Hamparan Masawit Bangun Persada (HMBP) is owned by palm oil conglomerate BEST Group.

"We again witnessed the brutality of the police in handling conflicts when Indigenous communities face companies," said Indigenous rights NGO AMAN in a statement issued over the weekend.

"One life was lost and two others were injured by police bullets."

Central Kalimantan police did not immediately respond to request for comment but local media quoted a spokesperson denying the use of live fire.

AFP was unable to reach HMBP.

Wahli called on Jakarta to re-evaluate HMBP's licence, while Amnesty International Indonesia demanded a probe.

"Bring to justice and punish apparatuses who were involved in the excessive use of force... which resulted in fatality and injuries," Amnesty's ex