Dozens of refugees released from detention

The immigration minister has revealed 80 immigrants have been released from indefinite detention after the High Court overturned a two-decade-old decision.

On Wednesday, the court found indefinite immigration detention was unlawful, giving hope to detainees who could not return to their home country.

Andrew Giles said the government was prepared for this outcome and revealed 80 people on appropriate visa conditions had already been released.

"We have been required to release people almost immediately in order to abide by the decision the High Court has required us to make," he told ABC radio on Monday.

The government will act consistently with the court's orders but was also considering its response to the decision, Attorney-General Mark Dreyfus said.

Opposition spokesman for Home Affairs James Paterson
The Opposition's James Paterson says some of the released refugees have committed serious crimes.

But opposition spokesman for home affairs James Paterson said the government was not adequately protecting Australians from the potential threats the newly released immigrants pose.

"We don't know who they are, we don't know where they are, we don't know what crimes they have committed," he said on Monday.

"We do know some of them have committed serious, violent and sexual crimes and others have violated the character provisions of the Migration Act - so much so that many other countries in the world are unwilling to take them.

"And now they're now being released onto the streets."

The government could examine the terrorism framework to apply control, supervision or continuing detention orders, or even introduce a form of electronic monitoring to give the community confidence, Senator Paterson said.

But Mr Dreyfus assured Australians that safety would remain at the forefront of the government's response.

"I can assure the Australian community the first priority of the government is to keep our community safe," Mr Dreyfus told reporters.

Those released would be required to regularly report and engage with the Australian Federal Police, Border Force and any other relevant bodies like state and territory criminal justice agencies.

"What we need to do now we have this decision - which has changed the law of two decades standing - is to work through it appropriately," Mr Giles said.

The legal decision was delivered after a Rohingya man from Myanmar brought the case to the High Court.

He faced the prospect of detention for life because no country would resettle him due to a criminal conviction for child sex abuse.

There were at least 92 detainees in a similar situation to the plaintiff and another 340 in long-term detention.