The UN Human Rights Committee says Australia must stop rejecting refugees and change its migration laws.
Australia needs to stop rejecting refugees and change its migration laws to come into line with international standards, the UN Human Rights Committee said in a report on Thursday.
The committee, which comprises 18 independent experts and monitors countries' compliance with a global human rights treaty, says Australia should come back in one year to explain what action it has taken to meet its concerns.
Australia has been widely criticised by the United Nations and rights groups for detaining asylum seekers who try to reach its shores by boat, even if they are found to be refugees, and keeping them on offshore processing centres in Nauru and Papua New Guinea.
The offshore detention policies are backed by the coalition government and the Labor opposition.
The United Nations has warned of a "looming humanitarian crisis" in the Manus island centre in Papua New Guinea.
It was closed on October 31, but 600 asylum seekers have refused to leave, fearing violent reprisals from islanders if they move to transit centres, pending possible resettlement to the United States.
The UN committee says Australia should significantly cut the period of initial mandatory detention and limit detention overall, and ensure that children are not detained except as a measure of last resort and for the shortest time possible.
"The State party should also address the conditions of detention in immigration facilities, provide adequate mental healthcare, refrain from applying force or physical restraints against migrants and ensure that all allegations of use of force against them are promptly investigated," it said.
Australia's 1958 Migration Act allows removal of an unlawful non-citizen regardless of the risk of returning them to a country where they may face death or persecution, the committee said, ignoring the principle of not sending refugees back to danger, known as "non-refoulement".
It urged Australia to ensure the principle was secured in law and adhered to.
The government could not be immediately reached for comment.
Immigration Minister Peter Dutton earlier told 2GB radio he stood by the detention policy that the government says is necessary to deter asylum seekers from attempting perilous sea voyages to Australia, and that it would not back down from its evictions from Manus.
The committee was concerned about conditions in Manus island and in Nauru, citing serious safety concerns and instances of assault, sexual abuse, self-harm and suspicious deaths.
Australia should also consider closing the Christmas Island detention centre, which was too remote to ensure protection of people held there, it said.