Papua New Guinea's Supreme Court has rejected a former prime minister's legal action against the Ok Tedi mining act.
The act allows the government to expropriate the PNG Sustainable Development Programme's 63.4 percent shareholding in the large Ok Tedi mine, in Western province.
But Sir Mekere Morauta filed a challenge as a private citizen, arguing that the act was unconstitutional and invalid.
The Supreme Court on Friday rejected that challenge.
Sir Mekere says he is discussing the decision, and whether or not he will take any further action, with his lawyers.