A United Nations anti-torture review hearing into Australia has been dominated by concerns that asylum seekers are being sent to inhumane offshore detention centres on Nauru and Manus Island.
The UN Committee against Torture is in the process of assessing Australia's record as a convention signatory in Geneva for the first time since 2008.
The committee on Monday night sought further information on Australia's asylum-seeker policies, controversial counter-terrorism laws and the over-representation of indigenous Australians in prisons - amongst other issues.
Chairman Claudio Grossman, who heads a panel of 10 independent experts, raised concerns that conditions in offshore processing centres had been described by both Amnesty International and the UNHCR as "inhumane".
"They are actually in a place surrounded by fences? And you need a guard to move from one place to the other?" Mr Grossman asked, before requesting a copy of the guards' training manual.
Mr Grossman also questioned the Australian delegation on reports it takes 10 months for refugee claims to be processed on Nauru and two years in Papua New Guinea.
"That would produce tremendous anxiety in people," he said.
"I can't imagine the number of people that are there and don't know where they are or what is happening."
Australia's mandatory detention policy also went under the microscope.
"There is some kind of reaction every time we use the word mandatory. No discretion, everyone goes through," he said.
"We've always said that children do not belong in detention centres. Are you considering changing this?"
The committee also asked for an update on allegations of child sex abuse in the Nauru detention centre.
The overwhelming majority of the 10 committee members asked questions relating to Australia's immigration policies during the two-hour hearing - with the few that didn't advising the topic had already been thoroughly addressed.
The Australian delegation, headed by Ambassador to the UN John Quinn, will reply to the committee's concerns early on Wednesday morning (AEDT).
"You've given us a lot of homework to do," Mr Quinn said.
The UN committee is set to hand down its report card on November 28.
