The High Court has issued an interim injunction preventing the transfer to Sri Lanka of 153 asylum seekers who are missing on a boat bound for Australia.
The injunction, granted late on Monday in Sydney, applies at least until a hearing resumes on Tuesday afternoon at 2.15pm.
The asylum seekers are represented by Ron Merkel, QC, who argued to Justice Susan Crennan that the transfer was illegal because the asylum seekers had been deprived the ability to have their claims properly assessed.
But it was not clear whether the transfer has already taken place because Immigration Minister Scott Morrison has refused to comment and his lawyers told the court they had not received instructions.
A spokesman for the Minister said on Tuesday morning that ''the government notes the matter is before the Court and accordingly will be making no further comment''.
On Tuesday, Prime Minister Tony Abbott said that he could not comment on the High Court case but said he could assure Australians that "what we do is consistent with our legal obligations and safety at sea".
"The Labor Party and its activists, the Greens and their activists, they will try to disrupt the government's policies. They will try to do things that start the boats up again because that's in Labor's DNA but we promised that we would stop the boats," he told Channel Seven.
Earlier on Monday, Mr Morrison confirmed 41 asylum seekers had been handed over to Sri Lanka's military after being processed at sea but he refused to discuss the whereabouts of the 153 asylum seekers on another boat.
Sources said lawyers were representing the asylum seekers through their families and they have not been in touch with them since contact was lost more than a week ago.
The surprise court action followed an emotional plea from the father of a three-year-old girl on board the boat for Mr Morrison to reveal the fate of the passengers.
"I am desperate to know where my family is," the man said.
He claimed all on board would face persecution if they were sent to Sri Lanka. "I can't function at all not knowing,'' he said.
The legal move came as the president of the Australian Human Rights Commission, Gillian Triggs, announced plans to investigate the treatment of children on the boat if they were transferred to an Australian vessel before being returned to Sri Lanka. Thirty-seven children are believed to have been on board the boat, which has not been heard from since Saturday, June 28, and left Pondicherry in southern India, on June 13.
Professor Triggs expressed alarm that the "enhanced screening" process used to reject the claims of the boat of 41 Sri Lankans appeared in breach of international law.
A Sri Lankan police spokesman has reportedly said the group had been handed over to the police and would face court in the port of Galle charged under the Immigrants and Emigrants Act.
Professor Triggs' concerns were echoed by more than 50 legal scholars from 17 Australian universities, who released a statement on Monday declaring Australia's acions in clear violation of international law.
''We are profoundly concerned by reports that asylum seekers are being subjected to rapid and inadequate screening interviews at sea and returned to Sri Lanka. This raises a real risk of refoulement in breach of Australia's obligations under international . . . law,'' their statement said.
A defiant Mr Morrison maintained the enhanced screening process complied with Australia’s international obligations and was the same process used by the former Labor government.
Mr Morrison confirmed early yesterday that the 41 had been subjected to enhanced screening before being handed over to Sri Lankan authorities, but refused to comment on the fate of the second boat. He said that in one case it was recommended that ‘‘further determination’’ be made, but the Sinhalese man concerned requested to depart with the others.
Asked by Sydney broadcaster Ray Hadley if the 153 on the other boat would not be coming to Australia, he replied: “No one is coming to Australia Ray. You can certainly deduce that.”
Labor immigration spokesman Richard Marles maintained that enhanced screening process employed by the former government would have involved the asylum seekers’ claims being assessed on Christmas Island.
“Labor has concerns about the integrity of this new method of processing people at sea en masse and how this complies with Australia’s international obligations under relevant conventions,” Mr Marles said.
The secrecy surrounding the interception of the two boats will be debated by the new Senate on Tuesday, with the Greens moving a motion on Wednesday demanding more information and calling for an end to "current screening and transfer practices".
Greens immigration spokeswoman Senator Hanson-Young said: ''The government think they are above the law and they are holding the public in contempt. The court and the parliament now need to bring them into line.
''They are playing with people's lives - it is only right that the court and the parliament force the government to explain what is really going on.''
Two crossbench senators have signalled that they will not support a motion condemning the government's policies.
"We have two options when it comes to asylum seekers," Family First's Bob Day told Fairfax Media. "You have a bad option and a worse option. Go for the bad option, there are no good options."
Liberal Democrat David Leyonhjelm said he would not support any motion criticising the government for individual actions, labelling it "partisan politics" that he did not want to participate in. But he would support a motion for more information and transparency.
"I will support attempts to improve and increase transparency. I think that's a good principle to pursue," he said.
Senator Leyonhjelm said he did not like the government's model because it gave people hope that they could "come in the backdoor".
Palmer United Party leader Clive Palmer said on Monday that if people seeking refuge had been returned by force to a country they were fleeing from it would be a breach of the refugee convention.
Refugee lawyer David Manne said it was difficult to track the fate of returned asylum seekers.
''This is part of the problem that we've seen in Sri Lanka, with people being essentially summarily expelled there without proper due process,'' he said.
Lawyer George Newhouse says the 153 asylum seekers are "entitled to have their claims for protection processed in accordance with Australian law".
"The (Immigration) Minister cannot simply intercept their vessel in the middle of the night and ‘disappear’ them,’’ Mr Newhouse said on Monday night.
Mr Newhouse argues there are serious concerns for the safety of the asylum seekers if they are handed over, and is worried they will also be charged and potentially jailed.
‘‘In Sri Lankan jails, detainees are often subjected to torture and sometimes they never reappear,’’ he said.
‘‘We’re talking about a boat load of women and children, and I would have thought that the minister needs to think very clearly before he sends them into Sri Lankan jail.’’
SMH with AAP