SEXUAL assaults in NSW schools are increasingly being carried out by juvenile offenders, an analysis of crime statistics shows.

Children as young as four are displaying sexually inappropriate behaviour, as well as sexually abusing other children. And experts believe pornography may be to blame.

A national symposium next week on the harmful effects of online pornography on our kids will discuss what many experts believe is a “major public health issue” that should be addressed by all levels of government.

media_camera Trinity Grammar School.

The NSW Bureau of Crime Statistics and Research data for the 12 months to last September show juveniles aged between 10 and 17 carried out 56 per cent of the cases of sexual assault and indecent acts reported on school grounds.

In total, 33 juveniles were reported to police at both public and private schools, up from 21 the previous year.

Adults committed the other 44 per cent of cases.

Back in the same reporting period in 2006, the figures were reversed — 70 per cent of sexual incidents were carried out by adults, with juveniles accounting for 30 per cent. The difference is even starker 20 years ago, when juveniles were involved in only 11 per cent of cases.

The Daily Telegraph recently revealed Trinity school Year One boys were discovered stripping down in the toilets and performing sex acts.

Child advocate and author Melinda Tankard Reist, who will speak at the national symposium at the University of NSW, said the issue was now at “tipping point” because children were just a click away from hard-core pornography.

“When you have four- and five-year-olds in treatment programs to address inappropriate sexual behaviours inspired by pornography, you know you’ve got a problem,” Ms Tankard Reist said.

“If governments don’t act preventively they’re going to see significant blowouts in the health budgets in the future.”

Ms Tankard Reist, who gives talks at schools on the issue, said she recently had a Catholic primary school principal show her a group assignment carried out by a five-year-old boy in a class that featured a sexually explicit image of a woman.

“When you’re in an audience of little girls — 11 and 12 — asking about bondage and sadomasochism, and showing me on their mobile phones requests from boys for sexual images, there’s been a shift,” she said.

“Three years ago it used to be 15- to 17-year-old girls.”