The Malind-Anim Indigenous community are mounting a legal challenge to protect West Papuan ancestral forests from a planned commercial development.

The action has been taken against the Merauke regency, an Indonesian administrative division, who have seized control of the Malind's customary land in a move the country's largest environmental non-governmental organisation claims threatens the Indigenous people's very survival.

The hearing is progressing through its second week in the Jayapura State Administrative Court in the largest city in Western New Guinea.

Reports on the proceedings indicate the Merauke administration has defended its position in the courtroom, while Malind lawyers have argued the authorities failed to properly recognise Indigenous customary rights and the community's deep relationship with the forest.

Sekar Banjar Aji, the Malind people's plaintiff's chief lawyer, stated the filing of the Merauke regency's decree has disregarded the principle of free, prior and informed consent (as enshrined in the UN Declaration on the Rights of Indigenous Peoples). This term is an internationally-recognised principle protecting the rights of Indigenous peoples when governments and/or companies propose activities that could affect their lands, territories, resources or way of life.

The Malind people are seeking to have the permit set for food production revoked and to stop the proposed development, which they argue threatens customary forests, wetlands, and ancestral lands.

The Papua chapter of the Indonesian Forum for the Environment added the lawsuit is representing a "legitimate effort" by the Malind community to challenge a regional policy that may facilitate land-grabbing and "accelerate environmental destruction" across their customary land in the South Papua province.

The environmental non-governmental organisation is warning that large-scale land clearing and conversion for the National Food Security Project may severely damage rainforest ecosystems, wetlands and swamp water sources that have long sustained the Malind people's livelihoods, culture and social life. It is standing in solidarity with the Malind community while closely monitoring the ongoing court proceedings surrounding the affected forests for the customary rights holders of the land.

"(Merauke) regional government policies should prioritise the protection of Indigenous rights and environmental sustainability rather than paving the way for any environmentally-destructive investment projects," the Papua chapter of the Indonesian Forum for the Environment said in a brief statement.

The organisation has also thrown its support behind the case of a second lawyer - Emanuel Gobay - who is also representing the Malind-Anim people, describing the Indigenous community as having the last ecological stronghold in Merauke.

"The Malind tribe is the last bastion of ecological defence in Merauke," Mr Gobay said.

"Revoking their rights to customary land is tantamount to robbing their identity, culture, and the future of future generations in Papua," he said.

The Papua chapter of the Indonesian Forum for the Environment called on the judges in the administrative court to "remain independent, uphold environmental justice principles, grant the Indigenous community's claims in full, and to annul the Merauke regency's decree".

The organisation also urged the Merauke regency administration to review and revoke permits affecting customary lands and to focus on recognising and protecting Indigenous land rights.

It further called on civil society groups, students and concerned young citizens across the West Papua territory to continue monitoring the legal proceedings until the Malind people's rights are fully restored.

Five representatives of the Malind-Anim Indigenous community initially filed the lawsuit to put a halt to the decree, which approved the environmental feasibility of a prospective 135-kilometre access road in Ilwayab district of Merauke, as part of Indonesia's Ministry of Defence's project.

The National Food Security Project refers to a series of Indonesian government initiatives aimed at increasing domestic food production to ensure the country is less dependent on imports and better able to withstand disruptions caused by climate change, geopolitical events and global supply shocks.

One of the project's largest components has been the development of an extensive agricultural area in Merauke to deliver on crops for rice, sugarcane, corn (maize) and other possible food crops to be determined that may suit local conditions.

Supporters from the Indonesian government administrations argue the project could boost overall food production for a country of nearly 290 million people, generate greater employment, encourage investment in a underdeveloped region and to improve overall transport.

However, the project has attracted equal criticism from environmental organisations, United Nations officials and Indigenous groups acting for communities over suggested large-scale deforestation, impacts on biodiversity and carbon storage, potential loss of traditional livelihoods around hunting, fishing and gathering, and long-term environmental sustainability.