Could children in prisons be the next abuse scandal?

If the last few years taught us anything, it's that child abuse thrives in institutions where they can't speak out, are unwilling to do so, or won't be believed when they do.

To a certain extent, it is inevitable. Children are resistant to talking about what is happening right now. Very often, they distrust all adults, and don't differentiate between a social worker and a prison officer. In scandal after scandal, they report abuse years after it has taken place.

But that means authorities must be more imaginative about how to respond. We can encourage children to speak out, and minimise the likelihood of abuse in the first place, by investigating the reality of sex behind bars and following the evidence. That is not happening.

Independent investigators are barred from entering prisons. The Ministry of Justice has made it all-but impossible for journalists or researchers to get into jails. The Guardian recently spent eight months seeking permission for one reporter to go into a one institution. It was denied. The Howard League-organised commission into sex and rape behind bars requested authorisation to conduct a survey on the subject among prisoners. They were denied. We don't have the culture of openness necessary to study the prevalence of abuse in prison.

It's particularly important to get people into prisons or institutions holding young people, because we know the children are unlikely to report abuse to the staff themselves. A survey by the inspector of prisons and the Youth Justice Board found only a third would tell staff if they were being victimised by other children or by staff.

In its interviews with former prisoners, the commission received evidence of alleged abuse by prison staff in the 1960s and 1990s, none of which had been reported at the time. As in Medomsley detention centre, where hundreds of men have now reported to the police that they were abused, it is unlikely the reports emerge until it is too late.

There are people for children to speak to in the current system. Some have access to independent advocates. There is a formal complaints system and social workers in the prison for them to make an independent referral. They also have access to the Samaritans. Perhaps this is all we can do, but allowing in independent investigators would at the very least prove reassuring.

In the US, there is a newfound political focus on sex in prison. Their Review Panel on Prison Rape found 9.5% of children in custody reported one or more incidents of sexual victimisation in prison during the past year. Of these, 2.5% reported being victimised by another child and 7.7% by a member of staff.

The size of the institution is important. The smaller it is, the less likely there is to be abuse. The US panel found facilities holding over 100 inmates were nearly five times as likely to report victimisation as facilities holding fewer than ten. That's very disturbing in a UK context. All prisons for boys in England hold more than 130 children. The 'secure college' the government is pressing ahead with will hold over 300.

This is a baffling decision to have made. It goes against all the expert advice. Abuse is less likely to take place, and more likely to be reported, in small centres where staff can take a mentoring or teaching role over the children.

But going against the evidence is now par for the course. There is little information coming from the prison estate and little research done by authorities. Neither the National Offender Management Service nor the Youth Justice Board were able to supply information on the number of official complaints of sexual abuse in custody or the number of investigations, criminal charges or convictions following a complaint.

Instead it was forced to send a letter to Inside Times, the prison magazine, asking for people to write in describing their experiences. It then relied on evidence from voluntary and statutory agencies, prison governors, former prisoners, HM Inspector of Prisons, the Prisons and Probation Ombudsman, child psychologists and academics to put together today's report.

At the heart of the report is a simple idea: maturing in prison can be a brutalising experience. At the exact point where young people should be going through character-forming sexual and romantic experiences, they are trapped in a hyper-masculine environment, where sexual contact and physically intimacy are impossible.

A majority of these children have experienced multiple disadvantages, such as emotional or mental health issues or deprivation. Over a third have experienced abuse, neglect or been put on the child protection register. Twenty-eight per cent have witnessed domestic violence.

Prisons are violent places. Official research found a third of boys in prison felt unsafe at some point and a fifth said they'd been victimised, usually by being hit, kicked or assaulted. At Feltham prison, for instance, there was an average of two fights or assaults every day, including pre-meditated group attacks on individual boys.

Children are often disciplined for perfectly normal sexual behaviour, like masturbation or the possession of magazines like Nuts or Zoo. Homophobia was, predictably, very common.

We just don't know very much about the effect of prison on young people, but the evidence we do have suggests it brutalises them, trapping them in an aggressive environment without role models at a crucial period of their development. The evidence suggests it may very well increase the chances of them becoming sexual offenders later in life. There is a very strong argument to suggest that we should never imprison young people and that if we must it should be in very small institutions – certainly not the child super-prison the coalition is inexplicably pushing forward.

There is no reason to question the good intentions and professionalism of the staff who work with young people in prisons. But unless we have a culture of openness around detention – and are prepared to follow the evidence it throws up – we will not have done everything in our power to prevent abuse.

A Ministry of Justice spokesperson said:

"Prison inspectors and criminal justice experts visit prisons on a regular basis in order to scrutinise and conduct legitimate and important research. We take all assaults in prisons extremely seriously, monitoring all incidents and publishing data on a regular basis.

"We work closely with the police to help facilitate criminal investigations and all establishments for young offenders are subject to independent scrutiny, with safeguarding issues among the specific areas assessed."