An Australian mining advocacy group says it supports Papua New Guinea's tough stance on the Ok Tedi mine to deliver an environment plan.
The PNG's deputy prime minister Sir Moi Avei had told stakeholders that cabinet had voted to shut down the mine in 2010 for failing to deliver an environment management plan.
The Mineral Policy Institute's Executive director Techa Beaumont says acid rock drainage is affecting nearby Fly River communities.
The mine contributes about 25 percent to the national economy.
She says the government has to weigh up long-term damage to the environment against short-term economic gains and should get independent advice.
"It's particularly critical looking at the remaining life of the mine that you are going to grossly exacerbate this problem of acid rock drainage so the kind of trade off that might be made has to be quite carefully weighed up against the likely impacts that they can expect."
Techa Beaumont of the Mineral Policy Institute