The humiliating backdown came after Immigration Minister Scott Morrison told Parliament this month that ''on every occasion that may present, we will apply all of the policies we have to ensure that no venture successfully reaches Australia''.

Mr Morrison, who has refused to acknowledge the existence of the boat for weeks, confirmed the asylum seekers would be transferred to the mainland, where they will be interviewed by Indian officials.

''Until this process undertaken by Indian consular officials has been completed, the persons will remain in Australia,'' he said.

It follows Mr Morrison's meeting in Delhi this week with India's Home Minister, Rajnath Singh, and External Affairs Minister Sushma Swaraj, where they agreed to take back Indian nationals and would ''consider'' taking back the Sri Lankan nationals who were on the boat, Mr Morrison said.

But human rights advocates and lawyers questioned why it had taken the Abbott government four weeks and an ongoing High Court challenge to bring the asylum seekers to the mainland. ''This recent development shows that stranding a boatload of people in the middle of the sea, in an effort to 'stop the boats', has achieved nothing,'' said Graeme McGregor, Amnesty International's refugee campaign co-ordinator.

Human rights lawyer David Manne agreed, saying: ''This could and should have happened from day one.''

Lawyers working on the High Court challenge against the government's decision to detain the asylum seekers welcomed the news, but said it now cast doubt over whether core elements of the High Court challenge can proceed before the court.

Hugh de Kretser, executive director of the Human Rights Law Centre, said the legal team was currently assessing the impact on the case.

The case, which was due to continue on August 5, was to be the first comprehensive test of whether the government had the power to intercept boats on the high seas and whether it had the right to hold asylum seekers against their will and take them where it chose.

Fairfax Media spoke with passengers on the asylum seeker boat, which departed Puducherry in the south of India on June 13. ''We need some help,'' a female Tamil passenger said on June 27. ''We are refugees.''

Until now, Mr Morrison has consistently failed to provide any information on the boat's passengers.

''It is our standard practice, as you know under Operation Sovereign Borders, to report on any significant event regarding maritime operations at sea, particularly where there is safety of life at sea issues associated,'' he said on June 28. ''I'm advised that I have no such reports to provide.''

Mr Morrison then reported on Friday that under government policy, the asylum seekers would not be resettled in Australia.

He said Indian consular officials would work through their claims and ''I don't want to pre-empt the work they're doing''.

Fairfax Media understands an A320 Airbus has been booked to transport the asylum seekers from Cocos Island to Curtin detention centre in north Western Australia on Saturday.

The Curtin detention centre has widely been considered to be one of the harshest detention centres on the Australian mainland.

Greens immigration spokeswoman Sarah Hanson-Young said Mr Morrison was a ''spectacular failure by his own measure''.

Meanwhile, the government's now-monthly Operation Sovereign Borders update, which details the movement of ''illegal arrivals'' and successful people-smuggling operations, has not been updated for a month and six days.

But Mr Morrison said on Friday that in the past seven months there had not been a single successful people-smuggling operation to Australia.