An agency which aims to prevent child pornography and trafficking says new police powers to catch online sex offenders are long overdue.
From Monday, an amendment to the Crimes Act allows police officers to pose as children online so they can identify people trying to groom potential victims.
The amendment brings New Zealand into line with similar provisions in some Australian states.
Police say this law change clears up a previously uncertain situation involving online predators and what can be done to arrest them.
Ecpat Child Alert, which aims to prevent the sexual exploitation of children, says online grooming is a serious matter.
National director Alan Bell says the offenders create relationships which come to seem very real to their targets and the damage is deep and long-lasting.