The popularity of simulated incest pornography and videos with non-consensual behaviour in New Zealand is bad news for young people, a sex therapist says.
The Office of Film and Literature Classification has released a study of the 200 most-watched videos on popular site Pornhub.
It found 46-percent of the most viewed videos featured sex between step-siblings or parents, and 35-percent had unwelcome sexual behaviour.
Therapist and pornography researcher Jo Robertson says the trends are deeply troubling.
She said unfortunately the research showed that young people used porn as sex education.
"If you've got your 15-year-old who's learning about how to have sex and pleasurable relationships or romantic relationships from porn, then essentially they seeing something that was coercive, exploitative or non-consensual - but also had these incestual themes in it - this is very bad sex education."
Rape Prevention Education executive director Debbi Tohill said porn reinforced myths about rape.
"The things that we often see in porn are things like women like to be raped or they like to be strangled and that they suffer very few negative outcomes because of that.
"And I think that it's really concerning."
She said she wanted an age verification system brought in which required proof that someone was of age - similar to what's been looked at in the UK and Australia - something Mr Shanks said he was open to.
The office also today released information to help parents talk to their children about porn.
Ms Robertson said teachers, social workers, counsellors and nurses all desperately needed better training too - and it has to start now.
"There's kind of this context at the moment with all these adults sitting around having chats about 'what should we do' and, and 'what's the strategy' and that's really important.
"But in the meantime, you've got year upon year of young people seeing really problematic content, asking for help and us just literally still talking about it with each other."
The government has signalled it wants to toughen up rules to make it harder for children to access pornography
But Minister for Internal Affairs and Minister for Children Tracey Martin said right now its hands were tied.
"Literally at the moment our regulatory system has no power over this particular area.
"In many ways we're trying to we're trying to run to keep up with the internet."
The Education Ministry said it was refreshing its guidelines on how to approach talking to students about pornography - along with piloting new toolkits in 1000 classrooms in the first half of next year.