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 catch offenders trying to groom potential victims.
Police say the new provisions will clear up previous uncertainties in the law.
The national director of Ecpat Child Alert Alan Bell, says he believes grooming is an even more serious matter than a one-off event.
Mr Bell says groomers try to build relationships which come to seem very real to their targets, so the damage is deeper and longer-lasting.
Police minister Judith Collins says the amendment will bring New Zealand into line with similar provisions in Queensland and New South Wales.