The work and advocacy of Indigenous community leader Theonila Roka Matbob in working towards securing justice and a clean-up of the Panguna mine in Bougainville has been recognised with a 2026 Goldman Environmental Prize.

Often referred to as the 'Green Nobel', the award is one of the world's most prestigious, honouring the leadership and work of environmental activists globally. Announced on Monday, Theonila won in the island nations category.

"I am deeply honoured to receive this award on behalf of myself and the mine-affected communities," she said.

"This is a struggle for justice that I have taken up so that my children and the next generation of Bougainvilleans can hopefully inherit a better world than the one so many of us have grown up with."

A traditional landowner from Makosi, downstream of the long-closed mine, Theonila is the lead complainant among 156 Bougainville residents who filed a human rights complaint against Rio Tinto with the Australian government in 2020 over the mine.

Despite being closed for more than three decades, the Panguna mine — once one of the world's largest copper and gold mines — still contains vast amounts of waste and decaying infrastructure, continuing to affect thousands of people in the area.

During its operation between 1972 and 1989, more than a billion tonnes of waste were released into the Jaba and Kawerong rivers.

Rio Tinto was the mine's majority owner until 2016, when it divested and transferred its shares to the PNG and Bougainville governments.

In response to the complaint and pressure from activists, Rio Tinto agreed in 2021 to fund the Panguna Mine Legacy Impact Assessment (PMLIA). Undertaken by global environmental consulting firm Tetra Tech Coffey, the assessment found that, at some sites, violations of Indigenous peoples' rights to water, education and culture had taken place.

It found parts of the mine pit, levee, roads and old buildings were at extreme risk of collapse, with the potential to cause death and cut off access to medical care for local communities.

Theonila said the legacy of the mine "continues to impact every part of our lives".

"We live surrounded by mountains of mine waste that pollutes our lands and rivers, limiting where we can grow food, collect water and our ability to live safely on our own land," she says.

She called on Rio Tinto to "deal with this disaster so that our people can move forward," noting the company's funding of the PMLIA, as well as its acceptance of the mine's impacts and public commitment to remedying the situation, had been important steps.

"Now Rio Tinto needs to move urgently to implement solutions in partnership with our communities and government," she said.

"In recent days, Tropical Cyclone Maila has further destabilised the old mine levees, threatening nearby villages and has flooded communities downstream. We cannot afford to wait any longer for action to address this situation — peoples' lives are at stake."

Last year, Rio Tinto told National Indigenous Times a roundtable involving the company, the Autonomous Bougainville Government (ABG) and Bougainville Copper (BCL) was aimed at developing a "process for collectively remedying actual and potential impacts identified in the PMLIA Report" — including the design of a "potential remedy mechanism aligned with the United Nations Guiding Principles on Business and Human Rights".

The company said the parties were addressing "ageing infrastructure" and other priority issues highlighted in the legacy report.

"The ABG has launched an education awareness program to inform local communities and small-scale miners about potential geo-technical risks," they said.

The 156 residents behind the original human rights complaint were represented by the Human Rights Law Centre. Legal Director Keren Adams said the law firm was "proud to stand with Theonila and the people of Bougainville in their ongoing efforts to seek justice and have this longstanding disaster addressed".

"Theonila's tireless advocacy, together with other key leaders from the mine-affected areas, shows what is possible when people act with courage, determination and vision," Ms Adams said.

"Together, they have brought one of the world's largest mining companies back to the table and secured their support to address impacts that Bougainvilleans have been living with for decades."