Teenage terror suspects as young as 14 could be locked up for 36 hours without charge under a new law proposed by Victoria's government.
As part of a review of the state's counter-terrorism laws, the age a child could be held without charge and without a court order would be lowered from 16 to 14.
"This is not treating those people the same as adults though: it would be a 36-hour detention rather than four days. You'd have to go to the Supreme Court beyond that," Premier Daniel Andrews told reporters on Monday.
"We'd all prefer not to have to make changes like this, but this is the threat we face, this is the world that we live in."
The Law Institute of Victoria says the proposed changes raise serious questions.
"Stronger safeguards, including strict oversight from the courts, need to be in place to protect children if they are to be held in custody under these proposed new terrorism laws," a spokesman said.
The review - led by former police commissioner Key Lay and former Supreme Court of Appeal Justice David Harper - also proposes removing motive as an "essential element" of a terrorist act as defined under national laws.
"Police at the moment have to decide whether or not the motive exists and if there's any doubt about that then there is some doubt about the way police are entitled to act," Mr Harper said.
"That motive should be removed as an element of the terrorism act definition but motive will certainly remain a very important concern."
The Labor government will also take a proposal to the Commonwealth to create post-sentence supervision orders for terror offenders, similar to those imposed on serious sex offenders.
"That ability is not currently available in the terrorism space, where people have been convicted of terrorist offences or create a significant risk," Mr Lay said.
At a state level, a new support and engagement order would be created for people showing signs of radicalisation.
"There'll be some contention about some of (these changes) but ultimately they're what needs to be done," Mr Andrews said.
