Victoria Police has been given three years to track down everyone on the sex offenders' register and take their DNA and fingerprints.
And they won't need a court order to do it.
Under the changes to the Sex Offender Registration Act, police will have the power to force registered offenders to hand over DNA and fingerprints.
"DNA is the most effective tool, much more effective than fingerprints, and it will help to solve sex offending crime," Police Minister Lisa Neville told reporters on Thursday.
"(It) gives police three years to fill in those gaps and make sure we have every single sex offender with DNA and fingerprints collected in Victoria."
The tough new laws will also give police the power to search registered sex offenders and their homes to ensure compliance with their reporting obligations.
Police will be able to demand online passwords to help with searches.
The changes also cover teenagers, aged 18 and 19, who had been involved in a consensual relationship with a person who was 14 or above.
They will now be able to apply to court for an exemption not to be named on the register.
This comes after an 18-year-old man was convicted for having sex with his girlfriend who he believed was aged 16, not 14.
Ms Neville said about 200 teenagers over the period of the register would be able to apply for an exemption.
The change will bring Victoria into line with most other states including New South Wales and Queensland.
Opposition leader Matthew Guy says he needs to see more detail about the plan but signalled his support for the law changes.