Papua New Guinea's Frieda River cannot be mined unless its protection is guaranteed, the governor of East Sepik province says.
A Chinese-owned company plans to mine copper and gold on Western Province's Frieda River, which is a tributary of the huge Sepik River system.
Allan Bird has posted on Facebook that while he appreciates the revenue the mine would generate; the bottom line is the safety of the Sepik River.
The National newspaper reported him saying that if safety of the river could not be guaranteed, then mining could not happen.
Mr Bird said the Sepik River is not just a supplier of fish, turtles, prawns, eels and crocodiles but a spiritual icon for his people.
He said the Sepik was one of the last unspoilt rivers in the world and it would be stupid to knowingly destroy the environment in exchange for money.
Mr Bird said the responsibility for the safety of the Sepik River rests with the East Sepik government and the Sepik people and they take that responsibility very seriously.