Victoria's most violent criminals may be detained in jail for up to a week without charge if they are considered at risk of offending.
The new laws, to be introduced on Tuesday, are part of a $390 million pledge to overhaul the handling of the state's most serious criminals who post an unacceptable risk of offending again after jail release.
Under new emergency detention orders, offenders on supervision orders can be kept in jail up to seven days if they pose an imminent risk of committing serious sexual or violent acts.
This will apply, even if they haven't breached a condition of their order.
Offenders will be housed at a new secure facility being built at Ararat, which will provide treatment and interventions for up to 20 supervision order offenders.
The facility is due to open later this year.
The scheme already applies to serious sex offenders, and allows courts to order the continued detention of an offender, or impose supervision including electronic monitoring, curfews and exclusion zones.