A Sri Lankan refugee is making a High Court bid to challenge the indefinite detention of 51 refugees ASIO deems national security risks.
Melbourne human rights lawyer David Manne is leading the challenge.
Mr Manne says the case will test whether the Australian Security Intelligence Organisation is obliged to tell the refugees why they are considered security threats and whether their cases should be independently reviewed.
He says it will also test whether it is lawful to lock refugees up indefinitely.
"The law requires a fair process, which means knowing the case against you," he told ABC Television.
"A refugee is locked up indefinitely on the basis of a negative security assessment made under a secret process."
Mr Manne said it was like being sentenced to "life imprisonment without being charged, tried and convicted".
The court documents name five defendants - ASIO's director-general, Melbourne Immigration Transit Accommodation boss, Department of Immigration secretary, Immigration Minister Chris Bowen and the Commonwealth of Australia.
A spokesman for the minister declined to comment because the matter was heading to court.
Liberal frontbencher George Brandis said the applicants will have a "big hurdle" to clear.
"ASIO threat assessments are neither a judicial or quasi-judicial process," he told the ABC.
He said the opposition did not support weakening the powers of ASIO in making threat assessments.
Mr Manne's legal team successfully challenged the Gillard government's asylum-seeker swap deal with Malaysia, which led to the policy being scuttled and offshore processing of asylum seekers being cast in legal doubt.