A BBC Spotlight NI investigation has uncovered 731 photographs of Northern Irish schoolgirls on a pornographic website used by paedophiles.
The schoolgirls included pupils from 19 post-primary schools in Northern Ireland, including some of the best known grammar and high schools.
The schools covered a wide geographical area and all communities.
The photographs were those that girls had taken of themselves and their friends.
They were in normal situations, having fun both inside and outside school - pictures taken in innocence.
In some of the pictures underwear was exposed as well as some bare skin.
Neither the pupils, nor the schools, have done anything wrong.
The pictures appear to have been taken from legitimate social network profiles without their knowledge or consent.
On discovering the images in October, BBC Spotlight NI immediately passed information about the website to the PSNI's Child Protection Unit.
The programme also informed all the schools concerned.
The pornographic website had multiple galleries of the schoolgirls under provocative headings.
Within the galleries, explicit paedophilic comments were left under some photos.
Based in Israel
The website in question is registered to an offshore accountancy business in Cyprus, with its servers located in The Netherlands.
However, BBC Spotlight NI has discovered that it is actually based in and run from Israel.
When contacted and challenged by the programme about the presence of the images, the website removed them, but refused to divulge who had uploaded them.
When pressed further, a representative of the website located in America agreed to be interviewed by BBC Spotlight.
He said that the images were merely "risqué" and for the "fantasy" of its users.
BBC Spotlight NI showed the images to the former head of the Child Exploitation and Online Protection Centre (CEOP), Jim Gamble.
"Whoever is collecting these images and putting them within the context of this site has a real problem and, in my opinion, an extremely deviant sexual interest in children," he said.
"If I was to find this on someone's computer that they were uploading it, and I was still in the police, they would be arrested that day."
Mr Gamble also highlighted the potential dangers that could have been caused by the images being shared beyond the website.
"If you are saying to me do I think some of these images will end up in paedophile collections, then the answer to that is of course I do, yes," he said.
The Police Service of Northern Ireland said it was currently investigating.
BBC Spotlight NI will be broadcast on BBC One NI on Tuesday at 22:35 GMT.