The number of children who commit sex crimes is on the rise.
Campaigners say youngsters at risk of offending need more help, but why are they behaving in this way in the first place?
Up to a third of children who have been abused say the perpetrators are other children
A common misconception about child sex abuse is that it is perpetrated by adults.
Indeed, the issue of child-on-child abuse is almost a taboo subject.
But research shows it is far from unique. Between a quarter and a third of children who have been abused report that the perpetrators have been children, according to various studies.
Tink Palmer, director of the Stop It Now! campaign set up to help children who are abused and a board member of the Internet Watch Foundation, said: "People don't just start abusing when they turn 18.
"It is something that develops over the years and is caused by a variety of reasons."
But in recent years, clinics that offer counselling to children who display sexually abusive and harmful behaviour report an increasing number of cases involved the internet.
Dr Andrew Durham, who runs a service for Warwickshire County Council for children who have abused or are developing inappropriate sexual behaviours, says the web plays a part in the cases of about half of the 120 children he sees each year.
"It is so easy for children these days to view abusive sexual images that they would not have been able to get close to years ago.
"Children are pretty computer savvy and once you start viewing pictures, it leads to more hardcore ones."
Such a scenario is borne out by stories of children who have fallen into the trap.
Like many teenagers, Dan (not his real name) started using chat rooms when he was 16 and developed a friendship with someone who later transpired to be an adult.
The man began to send him pictures of porn and then later abusive images of children.
In an interview with Barnardo's, Dan admitted he did not find the pictures repulsive.
At about this time, he began developing friendships with younger children.
One day, when his parents were away, he suggested that they come to his house to play.
He then took indecent photographs of the children, telling them that this was 'part of a game'.
He was soon arrested and given help to overcome his behaviour.
Cases like this are rare - there have only been about a dozen cases where children have been arrested for child porn.
But Dr Durham say graphic and abusive adult porn can desensitise children to sex.
"People start thinking what they are looking at is normal. The sex becomes what is important, not the relationship.
"It is not healthy. We have seen children, some very young, who have looked at pictures and started acting out the things they have seen.
"But I think this is all about the wider sexualisation of society. Sex is everywhere now, in advertising, on TV. This does have an effect."
DS Robert Willis, who is part of the abusive images unit run by Greater Manchester Police, said: "I think we are storing up all sort of problems for the future.
"Parents have to take responsibility for what their children are doing on computers, putting the right security blocks in place."
But specialists who treat children at risk of abusing also say it is not solely about the internet.
Research commissioned by the Department of Health last year found children who abuse generally fall into two categories.
There are those who develop abusive patterns early on, before the age of 11. These are more likely to have been sexually abused, come from broken families and develop insecurity issues.
But those whose abusive tendencies date to their teen years seem to have had slightly different experiences and the reasons for their abuse is less obvious.
The research found they tended to misuse substances, and have mental health and behavioural problems.
Jonny Matthew, of the Taith project in Swansea, a partnership between Barnardo's and seven local authorities which uses talking therapies to help children at risk of abusing, said: "The reasons for this behaviour are many and complex.
"But what we know is that with the right help and support these children can often be prevented from going on to commit serious offences."