By Matt Siegel
SYDNEY (Reuters) - Australia's highest court will begin considering on Wednesday whether the policy of sending asylum seekers to the tiny South Pacific nation of Nauru for long-term detention is in breach of the constitution, a major challenge to the controversial policy.
The hearings at the High Court, which are scheduled to last two days, will test for the first time whether Australia has the legal right to participate in the offshore detention of asylum seekers - the backbone of its immigration policy for five years.
Asylum seekers have long been a contentious political issue in Australia, although it has never received anywhere near the number of refugees currently flooding into Europe as they flee conflict in the Middle East and North Africa.
Successive Australian governments have vowed to stop asylum seekers reaching the mainland, turning boats back to Indonesia when it can and sending those it cannot for detention in camps on Manus island in impoverished Papua New Guinea and on Nauru.
Harsh conditions at the camps, including reports of systemic child abuse, have been strongly criticised by the United Nations and human rights groups.
The case has been brought on behalf of a pregnant Bangladeshi asylum seeker, who was brought to Australia from Nauru because of serious health complications and is now being forcibly returned with her infant child.
"This woman has a 10-month-old baby and she wants to rebuild her life somewhere safe and somewhere where she can move on with certainty. It is abundantly clear that can't happen on Nauru," Daniel Webb, Director of Legal Advocacy at the Human Rights Law Centre, told reporters.
Nauru unexpectedly said on Monday that all 600 asylum seekers held there would be allowed to move freely around the island and that all their asylum applications would be processed this week.
New Australia Prime Minister Malcolm Turnbull said last month he was concerned about conditions in the camps but gave no indication of a major policy change. Immigration Minister Peter Dutton said Nauru's decisions were unconnected to the High Court challenge.
Australia has defended its detention policy as necessary to stop deaths at sea. No one processed at the Nauru or Papua New Guinea camps is eligible to be settled in Australia, even if they are found to be genuine refugees.
The camps have also been criticised because it has become almost impossible for outside observers to gain access.
An independent U.N. investigator postponed an official visit to Australia last month, citing a lack of government cooperation and "unacceptable" legal restrictions.
Some investors in the company that runs the camps, Transfield Services Ltd, have said they will push for greater transparency and oversight.