UPDATED 6.15PM The Prime Minister doesn't see pornography as being a significant problem for our young.

Auckland Grammar has introduced a healthy relationships programme, tackling the sticky topics of online pornography and consent.

The school started the programme last year, involving seminars for both teachers and parents, as well as their pupils.

The news follows revelations this week that boys from Wellington College were posting inappropriate comments about women on a secret Facebook page.

An investigation has been launched, and Rape Crisis and other agencies were called in to the school to educate pupils on healthy relationships and consent, after the posts were exposed.

One pupil posted: "if you don't take advantage of a drunk girl, you're not a true Wc [Wellington College] boy," and another said: "f*** women".

School principal Roger Moses has condemned the posts as "deplorable and appalling", and said they do not reflect the values of the school.

Auckland Grammar principal Tim O'Connor said his school adopted the healthy relationship programme into its health education after researching mental health and well-being among teens - and pornography addiction was highlighted.

"From the material I've read, too many boys are getting their sex education in the first instance from going online and viewing pornography," O'Connor said, citing statistics claiming 90 per cent of boys have accidentally or intentionally viewed porn, some as young as 12.

"And it's different to pornography of years ago if you're talking the clichéd stuff of centrefolds etc. We're talking now about digital pornography where it's overly aggressive and it depicts women in a really bad light. There's issues with consent and what consent means, because in a porn world there doesn't appear to be such a thing as consent.

"So there's some really good conversation to be had ... If we can ensure they know the difference between an online environment and a real environment and real relationships, as opposed to what they're able to click on at any time of the day or night on a device, then we're alerting them to what harm can be done by viewing pornography and the perceptions they get about relationships online."

The morally conservative Prime Minister Bill English was asked questions about the issue today. He said schools and families are the appropriate people to deal with the issue.

"Well look, it's not an easy problem for people to speak about or to see," he said.

"We don't see evidence of it being a fast-growing or overwhelming problem. Clearly there's been a big increase in access to pornography through the internet."