The Government is taking urgent action to fix a 2016 botch-up that saw hundreds of people taken off the Child Sex Offender Register earlier this year.
"The longer these offenders are off the register, the less ability police have to monitor them," Police Minister Poto Williams said today.
The changes to the current law will ensure that "all individuals who have committed a qualifying child sex offence, irrespective of when that offence occurred" will be put on the Child Sex Offender Register.
"We are taking urgent action for the safety of our tamariki," Williams said.
It comes after a Supreme Court decision last month that found the current law was not clear enough, meaning the rules did not apply to a person who committed a 'qualifying offence' before the law came into force in 2016, and were convicted and sentenced after.
"As a consequence of this decision, police has had to remove hundreds of individuals from the Child Sex Offender Register," Williams said.
"The whole purpose of the Act was to establish a Child Sex Offender Register that would reduce sexual reoffending against child victims, and the risk posed by serious child sex offenders, through monitoring of registered offenders."
"This urgent amendment will ensure that those for whom Parliament always intended to be on the register, will remain on the register.
"It will also ensure police can register individuals convicted of historical child sex abuse, which is particularly important in the context of the Royal Commission of Inquiry into Abuse in Care."