Prime Minister Julia Gillard says there is little chance any more people involved in the fatal Christmas Island boat accident will be found alive.
Thirty people died after a wooden fishing boat carrying as many as 100 Iraqis, Iranians and Kurds smashed into Christmas Island's Rocky Point in high seas on Wednesday morning.
There are 42 survivors.
Ms Gillard said given how much time had passed since the accident, it was unlikely any more would be found.
"We do need to face the grim reality that it is becoming increasingly unlikely and an increasingly remote possibility that survivors will be found at this stage," she told reporters in Sydney on Friday.
Ms Gillard said the search and recovery operation would continue until nightfall, and then emergency teams would decide whether or not to continue the mission on Saturday.
Three Indonesian crew survived the tragedy and are being interviewed by Australian Federal Police, she said.
"It remains unclear exactly how many people were on the vessel and we may never know that number with precision," Ms Gillard told reporters.
"Three survivors have been airlifted from Christmas Island to Perth overnight. I advised yesterday that there had been some movement of other survivors. So, that now brings to five the total number that have been airlifted to Perth for assistance.
"One is the husband of an injured woman who has also gone, obviously, to be with his wife in these circumstances."
Ms Gillard said arrangements were being made for a memorial service to be held, likely on December 19 or 20, to recognise the lives lost and to allow people to grieve.
The prime minister said she was mindful of the needs of the Christmas Islanders.
"Counselling services have been offered to Christmas Island residents who participated in the
rescue or witnessed the incident.
"A shopfront has been established on Christmas Island with professional counsellors to provide immediate assistance to community members who feel that they need their assistance."
Ms Gillard said she had asked for the chronology of events to be released so Australians had access to the information about the response.
The vessel was first sighted by Christmas Islanders and was not being tracked by authorities, she said.
Ms Gillard said Australia's search and rescue zone covered 10 per cent of the earth and the area in which asylum seeker vessels were likely to be encountered covered more than 1.4 million square nautical miles.
She said a Dash-8 surveillance aircraft could cover 50,000 square nautical miles in a seven-hour mission.
"With such a big area it is possible for a boat to get to Christmas Island and not be detected," she said.
Ms Gillard said radars aboard navy and customs patrol vessels were affected by bad weather and in this case, it was not effective to detect the asylum seeker vessel before it reached Christmas island.
She said there was great interest in the criminal investigation of this incident and the prospects of bringing the people smugglers who organised this venture to justice.
"I am advised by relevant agencies that the investigation is progressing, that Australian authorities are working closely with the people smuggling task force from the Indonesian national police," she said.
"This collaboration has been successful in the past, with the arrest of 112 people smuggling organisers in recent years."
Ms Gillard said a multi-party parliamentary group she wants to set up to respond to the tragedy would include government, opposition and Australian Greens members, as well as one representative independent politician.
"What that group would do is it would receive reports from the agencies that are involved in managing the incident," she said.
"I want people to have the facts, I want parliamentarians to have the facts, I want the Australian public to have the facts."
Ms Gillard said the group wouldn't manage the incident, write reports about it, make recommendations or deal with policy questions, but receive reports and "get the facts".
"That would be in addition to, on top of, the normal protocols about briefing the opposition on matters like this," she said.
Ms Gillard stressed she wanted to avoid repeating the confusion that surrounded the 2001 children overboard affair.
Ms Gillard said she spoke to independent MP Rob Oakeshott on Friday morning about the purpose of the group.
Mr Oakeshott said on Friday Ms Gillard must deal with the rumours swirling around the tragedy.
Ms Gillard said: "I will be writing today to make sure that this matter is absolutely clear to the leader of the opposition, the leader of the Greens, obviously Senator Brown, and to the independents to make sure that they've got full details of the proposal I've outlined."
Ms Gillard said she spoke to independent MP Rob Oakeshott on Friday morning about the purpose of the group.
Mr Oakeshott said on Friday Ms Gillard must deal with the rumours swirling around the tragedy.
Ms Gillard said: "I will be writing today to make sure that this matter is absolutely clear to the leader of the opposition, the leader of the Greens, obviously Senator Brown, and to the independents to make sure that they've got full details of the proposal I've outlined."
