The operator of Papua New Guinea's Hidden Valley Gold Mine in Morobe province says it's co-operating with authorities to identify the cause of dead marine life in a major riverway.
The Morobe Mining Joint Venture had its mine operations stalled late last week due to a road block by locals at Markham Bridge.
The locals from a village near the confluence of the Watut and Markham rivers claim the mine, which is 160 kilometres away, is to blame for poisoning their waters.
A team from the Department of Environment and Conservation is investigating.
MMJV, a joint venture between Australian company Newcrest and Harmony Gold of South Africa, says there's nothing to indicate the mine's involvement.
It says the quality of water discharged from the mine is monitored on a daily basis and that it is in compliance with the Department's standards.
MMJV says the greatest current impact on the local river system is the Kumalu mudslide where cubic kilometres of sediment have entered the river due to heavy rain.