Justice Minister Judith Collins says judges will be given more powers in new legislation targeting child abusers who distribute images of indecent acts.
A bill being introduced in Parliament this week will increase prison sentences for those who share images of child abuse, as well as those who download and view the material.
The legislation doubles the maximum penalty from five to 10 years' jail for possession, import or export of objectionable material.
Ms Collins told Radio New Zealand'sMorning Report programme the changes will act as a deterrent to predators who harbour and receive child sex abuse images.
She says 400 people were convicted of an objectionable material offence between 2004 and 2011, mostly involving child sex images. Of these 33% received a prison sentence, which Ms Collins says is totally unacceptable.
Ms Collins says the law will always be running behind advances in technology, but the changes will close loopholes and allow judges to hand out harsher penalites.
The founder of the Stop Demand organisation, Denise Ritchie, says tougher sentences were introduced in 2005, but a series of decisions by some judges who did not grasp the gravity of the offending meant up to half were being given community-based sentences. She says the changes will help prevent this from continuing to happen.
The director of ECPAT child alert, Alan Bell, says there is a growing trend towards younger victims, including toddlers and babies, as well as more violent acts and an increase in boys being abused. Mr Bell says cracking down on the demand for such images will hopefully affect supply.
A new offence will also make it illegal to communicate indecently online or through text message with a child under the age of 16 .
Child Matters executive director Anthea Simcock says some people will claim they're unaware of a child's age, but she says there is no excuse for this sort of behaviour.