Ranjini, the Sri Lankan mother of three who has spent more than three years in detention after being deemed a national security threat by ASIO, has been freed.

The Tamil refugee was given no reason why she was considered a security risk when when she was whisked into detention in May 2012  - and was similarly given no explanation for her unannounced release on Thursday.

"She is very happy and extremely relieved," her lawyer, David Manne, said on Friday after Ranjini's first day of freedom included walking her two older boys, aged 9 and 11, to school.

Her third child, an Australian citizen, was born in detention after the pregnancy was confirmed two days after she was flown with her boys from Melbourne to Sydney's Villawood detention centre.

Ranjini was one of more than 50 Tamil Sri Lankans who were deemed security threats despite having refugee status and were then indefinitely detained. Most have since been quietly released without reason after their adverse security assessments were lifted.

Although Ranjini's husband Ganesh is an Australian citizen and she is recognised as a refugee, she does not know what visa she will be offered. 

"She is looking forward to being able to rebuild her life with her husband and three boys with certainty of a safe future," Manne told Fairfax Media.

Ranjini, 36, whose first husband died in the Sri Lankan civil war, arrived on Christmas Island in April 2010 and spent time with her two boys in detention centres in Perth and Adelaide before being released into community detention in Brisbane in April 2011.

Her refugee status was recognised six months later.Then, with the apparent blessing of immigration officials, she married Ganesh, a Tamil refugee she met in Brisbane, moved to Melbourne and enrolled her two boys at Mill Park Primary before ASIO deemed her a security risk.

A High Court challenge to her indefinite detention found an error of law had been made in her case, but did not reopen the question of whether her indefinite detention was lawful.

Manne said the family had endured "profound distress" while she was in detention and she remained concerned about those whose adverse security assessments remained in force.

Trevor Grant, a convenor at the Tamil Refugee Council said: "We are overjoyed to see Ranjini released. I spoke to her by telephone last night and see was laughing and giggling so much it was hard to understand her.

"She has shown great courage and resilience, being forced to bring up three children behind bars for most of her time in Villawood. Her husband Ganesh has been equally strong. We are confident they will recover.

"But justice still has not been done. As the UN demanded more than two years ago, all these indefinitely detained refugees not only have to be released but also compensated. We will continue to campaign for this."

Grant said the incarceration of more than 50 ASIO-negative refugees, most of whom were Tamil, had been a stain on this country's democracy. "As far as we are concerned, it was part of a political stunt designed to scare off Tamil asylum-seekers," he said.

(WAtoday.com)