WELLINGTON, March 10 - Four Year 9 boys at St Patrick's College Silverstream have been suspended after they allegedly "inappropriately filmed" two female staff members.

Days earlier Wellington College was forced to act when students were reported for posting sexist and degrading comments on a closed Facebook page.

One post allegedly said "If you don't take advantage of a drunk girl, you're not a true Wc (Wellington College) boy", and another "F*** women".

"We're appalled by the comments made on Facebook by students at Wellington College and by the sharing of highly inappropriate photographs of two female staff members on Instagram by students at St Patrick's College Silverstream," Ministry of Education deputy secretary Katrina Casey told media in a statement.

"Both incidents indicate a casual disregard both for issues of consent and for young women as people, not just sexual objects."

The ministry has been in contact with the schools about the incidents and supports the internal discipline approach being taken by school leaders.

As well as dealing with individual boys, the schools are assessing whether deeper issues of consent and respect for young women also need to be addressed.

St Patrick's College Rector Gerard Tully confirmed on Thursday the school had been dealing with a "most distressing incident of sexual harassment" involving four Year 9 boys.

"The students involved have been suspended from school, pending a hearing with the Board of Trustees Discipline Sub-Committee," he said in a statement.

The ministry says it revised sexuality guidelines in 2015, and updated advice to schools on the importance of teaching about consent, coercion and sexual violence.

"We recognise understanding what consent means is an important (matter) in the education of young people," Casey said.

Prime Minister Bill English is a former St Patrick's College student and said he was concerned about the reports but said the college looked to be moving to deal responsibly with the matter.

"There's always an element with people in their early teens doing things that show bad judgement ... but I think it's really important that those young people get a clear message that that kind of behaviour is unacceptable," he said on Thursday.

"The school's making their stance clear. That's the right thing to do and I hope those young people learn a lesson from it that it's unacceptable."

The ministry is not aware of any similar investigations at any other schools.