A group of 89 Iraqis, Sri Lankans, Afghans and Iranians was transferred from Christmas Island to Villawood Immigration Detention Centre in Sydney on Saturday, after they were found not to be refugees.
Those who are yet to have their claims independently reviewed will be able to go through the process at the high-security centre.
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Opposition immigration spokesman Scott Morrison says bringing the men to Australia's mainland is risky because it could open new legal avenues for them to prevent deportation.
"It has not been tested in a court yet whether their status changes," he told ABC Radio.
But Refugee and Immigration Legal Centre solicitor David Manne, who represents 17 Sri Lankans still having their cases independently reviewed, said it was unlikely their status had changed since coming to mainland Australia.
Deportation flights from mainland
"The legal framework was designed to essentially say that if you first come to an excised part of Australia like Christmas Island... then that's the legal situation that you stay in for the duration of your processing," he said.
But Mr Manne wouldn't rule out challenging the status quo.
"We will always... explore all legal avenues," he said.
Immigration Minister Chris Evans said the rejected asylum seekers' status would stick.
"Their status remains... they're offshore entry persons," he said.
Senator Evans said most people who had their refugee claims rejected had to be brought to the mainland because that was where flights home departed from.
Christmas Island was almost full, he admitted, but some new beds would soon become available.
Senator Evans said he didn't expect the flow of boats to stop anytime soon.
