The Australian government stood firmly behind its controversial policy of mandatory detention for illegal immigrants, despite a string of scandals in which its citizens have been accidentally deported and jailed.

Immigration Minister Amanda Vanstone rejected calls to soften the conservative government's immigration policies, telling reporters that the mandatory detention policy would remain.

"We have a policy of mandatory detention," Vanstone told reporters. "We are absolutely committed to stopping people smugglers bringing people to Australia through the back door."

Speaking in parliament, Prime Minister John Howard also defended the policy and said Vanstone had his full support despite calls for her resignation.

But not all government backers were convinced.

A lawmaker from Howard's Liberal Party, Petro Georgiou, said he would submit bills this week that would require the release of women, children and long-term detainees from immigration camps.

Ex-Qantas stewardess jailed

The government's policies of mandatory and unlimited detention for illegal immigrants introduced in 2001 have been credited with stopping the flow of boat people making their way to Australia from troublespots such as Iraq and Afghanistan, often on dangerously dilapidated vessels.

But the policies have been attacked by human rights groups, and many detainees have remained in immigration limbo in outback detention centres for several years.

The issue has received renewed coverage following reports that Australian woman Vivian Alvarez, 42, was wrongly deported to the Philippines four years ago and was only found earlier this month in a hospice for the dying there.

A second Australian resident, German-born Cornelia Rau, has also said she will seek compensation for her wrongful 10-month detention as an illegal alien.

Speaking at a press conference in Adelaide yesterday, Rau said she had been mistreated while in custody, at one point fearing for her life.

The former Qantas first-class flight attendant said that at the Baxter immigration centre she was "locked up in a cage like a caged animal".

"I think this country has a lot of problems for the poor people who've wanted to actually come here as refugees," she said.

Meanwhile, the government yesterday released a three-year-old girl who had spent her entire life so far in a detention centre, after her Malaysian mother was detained in 2001 for allegedly trying to travel on a false passport.

32 wrongful detention

A closed inquiry into the Rau case has been extended to include those of Alvarez and 32 other cases of wrongful detention, but the government has rejected calls for a full and open investigation of the cases.

Vanstone said the Alvarez and Rau cases were unique because both contained extremely unusual circumstances.

"Having said that, in a review of those cases with extremely unusual circumstances, if you find an administrative or cultural approach that needs improving then it's appropriate you make those changes," she said.

Vanstone said Canberra had the third highest planned intake of refugees in the world and was determined the system would not be undermined by people smugglers providing passage to Australia to the highest bidder.

She said negative publicity about the cases could be damaging to Australia's reputation, but the government believed its policy was correct.

"We will take those most in need, we will put them first... doing it the way we do it is harder," she said. "We have to put up with a lot of criticism and a lot of misunderstanding.

"But when I go to sleep at night and I say to myself 'we're remaining strong against people smugglers, and we're taking those most in need' I sleep like a baby."