The Refugee Action Coalition says a challenge to the legality of Australia's asylum seeker processing centre on Papua New Guinea's Manus Island is a welcome development.
Lawyers acting for the opposition leader, Belden Namah, have asked the court in Port Moresby to permanently restrain the PNG government from detaining people at the centre.
The Australia-based Refugee Action Coalition's Ian Rintoul says the situation on Manus gets worse by the day and if the challenge is successful it will be a step forward for human rights.
But he says he expects PNG's Prime Minister, Peter O'Neill, will change the law to get around any Court decision that rules the detention centre unlawful.
"I think that would probably be the first thing he'd try to do, and that's exactly what the Australian government has done when courts have found that their actions have been unlawful and I'm sure the Australian government would encourage O'Neill to do exactly the same thing. But just looking at the composition of the parliament he might find that quite difficult to do."
The Refugee Action Coalition's Ian Rintoul.