There have been 174 sexting offences recorded since the laws came into effect, and around 29 per cent of alleged offenders were minors aged between 10 and 17, according to figures from the Crime Statistics Agency.

While the bulk of these young alleged offenders were given warnings, seven children have been charged with sending or threatening to distribute explicit images without consent over the past 15 months.

It comes as police investigate an Instagram account set up by two year 11 students at Brighton Grammar School which featured photos of young girls and invited people to vote for the "slut of the year".

Similar accounts have been set up by students at other schools. One father, who did not want to be named, said his young daughter was shocked to discover that a sext she sent her boyfriend was uploaded on to a pornographic Instagram account.

"It was devastating," he said. "She was humiliated. These photos of girls were being passed around like football cards."

Australia's first sexting offences came into effect in Victoria in November 2014 following a parliamentary inquiry into the phenomena.

The new laws included exceptions to child pornography offences so that minors who sent or received raunchy but non-exploitative sexts were not placed on the sex offenders register.

The parliamentary inquiry was triggered by Fairfax Media reports of young people whose career prospects were shattered after they were caught with intimate images and placed on the register.

Academics have warned that social media such as Snapchat had made it harder for schools to deal with sexting and cyber bullying, because the evidence appears to disappear.

University of New England education academic Dr Sue Gregory, who is conducting a large study on the impact of Snapchat in schools, said principals were confronting extremely sensitive issues.

She said that the dangers of sexting needed to be discussed with children when they were in primary school.

Victoria Legal Aid Youth Crime Program Manager Anoushka Jeronimus agreed.

"We know that young people have access to smartphones and tablets at a young age. That means the education that accompanies that usage need to happen early," she said.

"There's no point teaching them at year 9."

Legal Aid runs a Sex, Young People and the Law program in Victorian secondary schools which teaches students about consent and the dangers of sexting.

"The message is to be cyber safe and to know the consequences of your actions. In some cases, they can have criminal consequences."

A police spokeswoman said transmitting any intimate image without consent was a crime.

"Those young people who seemingly willingly text their naked image or sexual references often do not consider the longer term consequences of the image or information being in a space outside their control for years afterwards," she said.

She said the police had dedicated youth resource officers who supported and educated young people, their families and schools to ensure they were safe.