A group of Rotorua teenagers have been counselled by police after inappropriate "sexting" messages were discovered on a boy's mobile phone.
It has prompted warnings for parents to remind their kids about the risks of technology.
Sexting is sending sexually explicit messages, photos or videos via mobile phones. It's an issue on the rise around the world.
Some Australian teens reported exchanging naked images of themselves as they enter relationships - as a form of "insurance" to ensure they can retaliate if anything inappropriate is passed on about them.
A Rotorua police officer was called to investigate inappropriate images found on a schoolboy's mobile phone last month.
The images were found when the phone was confiscated after he used it during school hours. A teacher saw photographs on the device of what they believed to be girls under 16 in various states of undress.
The boy said they were local girls and he was not the only boy to have received their images. He claimed almost half a dozen boys in the city had seen them.
A police spokeswoman said no charges were laid. Those involved were counselled.
The police officer who dealt with the case said he was unable to comment and referred the paper to Rotorua's area commander, Inspector Bruce Horne.
Horne said police did not wish to comment on the specifics of incidents of this type, given the young age of those involved. However, he urged all parents to take an active interest in their children's use of technology - from cellphones to online forums and social networking websites.
He said it was important that children explored their independence but it was "absolutely vital" that adults in their lives tested their decision-making and ensured they made informed and safe decisions.
"While our young people do have to take responsibility for making the right decisions about keeping themselves safe, parents also share this responsibility," said Horne.
"Make sure you know what your teenager is doing, where they are and who they are with."
Zane Scarborough, the manager of the Attitude programme - the youth division of Parents Inc - lectures high school students nationwide on the downfalls of technology. He had no doubt sexting was happening in schools.
"As technology improves, the issue rises," he said.
He said kids needed to resist peer pressure to send such images.
It was likely the person they sent an image to would show others - and the photos could stay around for a long time.
A police spokeswoman said charges could arise from sexting, depending on the age of those involved and the nature of the alleged offence.