Bring detainees to Aust: rights group

Asylum seekers held on Nauru and Manus Island should be brought to Australia amid a legal system breakdown, a leading human rights specialist says.

Nauru's only magistrate, Australian citizen Peter Law, was sacked by the Pacific nation's president, sparking criticism across the region.

The move leaves in limbo more than 100 asylum-seeker cases, including those accused of rioting in 2013, when extensive damage was caused to the detention centre including the torching of new accommodation blocks, the health centre, offices, the dining room and vehicles.

Australian Human Rights Commission president Gillian Triggs said Australia was obliged to ensure the safety and rights of the asylum seekers it had sent to the islands.

"Australia should ensure that adequate safeguards are in place in those countries at all times, including the application of the rule of law," Professor Triggs said.

She added that the commission was concerned about asylum seekers who remained on Nauru, particularly those facing riot charges.

More than 2000 people are detained at offshore processing centres on the two islands.

Immigration Minister Scott Morrison said internal Nauruan politics were behind the island's legal upheaval.

"My best understanding at the moment is that it has nothing to do with how he was dealing with any asylum cases that are before him," Mr Morrison said of Mr Law's sacking.