A landowning group at the site of Bougainville's Panguna Mine says it has referred the government's controversial mining plans to the Papua New Guinea Ombudsman.
The Osikaiyang Landowners group said amendments to the Mining Act, due for consideration in parliament this week, would effectively reverse customary law on the ownership of minerals.
Bougainville's government has argued that what it is planning, in conjunction with Australian businessman Jeff McGlinn, will ensure landowners are better off.
But the Special Mining Lease Osikaiyang Landowners Association said this amounted to an abuse of executive power, the Bougainville Constitution and the PNG Constitution.
Osikaiyang chair Philip Miriori said the group would never allow others to "steal our land, our minerals and both our future and our heritage".
The amendments are defective and the people pushing them, such as Mining Minister Raymond Masono, are breaching the Leadership Code, which is the basis for the appeal to the Ombudsman, Mr Miriori said.