The release of a depressed child from an Australian detention centre, after she started banging her head against a wall, has sparked calls even from within the government to end mandatory detention of illegal arrivals.
   
Three-year-old Naomi Leong, who was born in the Sydney detention centre, and her mother Virginia were unexpectedly released on Monday night.
   
"I think that the detention environment drives people mad and we've got fairly substantial evidence of that now," psychiatrist Jon Jureidini, who has assessed detainees, said on Tuesday.
   
Australia is a nation built on migrants but it has one of the world's strictest immigration policies, detaining illegal arrivals, illegal workers and people who overstay, sometimes for years while their cases are heard.
   
The government has given no reason for the release of Naomi Leong. Her mother had overstayed her visa and been ordered to return to Malaysia, but refused to leave fearing her daughter was stateless and would not be allowed entry to Malaysia.
   
"It's a dream come true," said Virginia, as she played with Naomi in a Sydney park on Tuesday.
   
The emotional issue of mandatory detention saw splits surface in the government, with two ruling MPs raising the issue in a party meeting with conservative Prime Minister John Howard. One Liberal MP said he planned a private legislation to end mandatory detention and make the policy more compassionate.
   
"Asylum seekers have been detained for periods longer than the prison sentences imposed on violent criminals...," Petro Georgiou said in a statement. "The harmful effects of long-term-detention on detainees' mental and physical health has been documented by health experts."
   
Petro said his bill would see detention only under judicial scrutiny and women, children and long-term detainees released to await an immigration decision.
   
But Howard told parliament later in the day that there would be no change in policy. "We continue to adhere to a policy of mandatory detention," he said.
   
Australia's immigration detention camps, which have been condemned by international human rights groups, have been hit by protests, hunger strikes, riots, escapes and suicide bids as asylum seekers become frustrated at delays in hearing cases.
   
"Let children go"
   
Opposition Labor leader Kim Beazley said the government should at least end the detention of children. "Kids don't belong in detention," he said. There are more than 60 children in detention.
   
The tough stand against illegal immigration and people smuggling has helped Howard win four straight elections.
   
The policy was first introduced to deter boatpeople trying to land on Australia's remote northwest coast, but was later justified as necessary for security reasons post the September 11, 2001 attacks in the United States.
   
Naomi Leong's release came as an Australian woman wrongfully detained for 11 months as an illegal immigrant said she felt like a "caged animal".
   
Cornelia Rau, who is suffering a psychiatric disorder, said she would seek compensation from the Australian government for her detention in an outback immigration centre.
   
The Australian government has admitted at least 33 Australians have been wrongfully detained in the past two years.
   
"The disturbing catalogue of wrongful detentions and deportations demands, at the least, an independent review of all long-term detainees," said Labor's immigration spokesman Laurie Ferguson.