Australia will indefinitely detain people convicted of terrorism-related charges if it feels they pose an ongoing danger to society upon their release, Prime Minister Malcolm Turnbull said on Monday.
Turnbull compared the measures to those employed against some child sex offenders and cited what he called a growing number of attacks such as the recent Bastille Day attack in Nice, France, that killed dozens.
"Together the measures that we're announcing today are designed to deter terrorism, prevent it, ensure that the nation and our people are kept safe and to provide reassurance that Australians can and should continue going about their daily lives and enjoying their freedom in the usual way because they should understand and recognise that the Australian Government and it's agencies are doing everything possible to keep them safe," Turnbull said on Monday.
"The existence of post sentence preventative detention as a measure will serve as a very real incentive for those imprisoned for terrorist offenses to reform. It will provide a very real incentive for people imprisoned for terrorist offenses not to engage in continued extremist activity."
Attorney General George Brandis, speaking with Turnbull in Sydney, said indefinite detention would be decided by a court-supervised process, which included medical and psychological assessments, and details of a prisoner's behaviour in custody.
There will be a periodic review, an annual report to parliament and a statutory review of the efficacy and need for the scheme after the first several years, Brandis said.
"Of course, the issue of radicalisation while in imprisonment is an important issue, and that is a matter which the states and territories which manage prisons have in hand. But as the Prime Minister said before, one of the virtues of the post-sentence detention regime scheme that we are proposing is that it provides very powerful incentive to people who may be in prison not to participate in further radicalisation, or not to renew their malevolent intent, but rather gives them an incentive to be genuinely rehabilitated because they face the risk that if they continue to demonstrate these attitudes, these intentions that they may very well find themselves the subject of an application for preventative post-sentence detention," he added.
A staunch US ally, Australia has been on heightened alert for attacks by home-grown radicals since 2014, having suffered several "lone wolf" assaults, including a cafe siege in Sydney in which two hostages and the gunman were killed.
About 100 people have left Australia for Syria to fight alongside organisations such as Islamic State, Australia's immigration minister said last month.