Hundreds of children are alleged to have been abused and neglected in prison over the last three years amid a dramatic rise in young offenders being injured.

There were more than 550 allegations of child abuse or neglect made against staff in England’s seven child prisons between 2016-17 and 2018-19, according to figures obtained through freedom of information (FoI) requests to local councils by charity Article 39.

And the number of restraint incidents that have resulted in children suffering injuries or compromised breathing have more than tripled since 2014, from 54 to 193 last year, according to data obtained by charity Article 39.

Young offenders are being failed by a system that is starved of resources and facing a “calamitous” turnover of staff, campaigners say.

The number of children being physically assaulted by prison officers is increasing despite a considerable drop in the child prison population. Government statistics show there were 1,157 young offenders in custody in 2013-14 compared with 832 in 2018-19 – a decrease of 28 per cent.

Experts speculated that the increase was in part due to improved reporting of serious incidents by prison staff, but said such a dramatic rise was also down to a lack of funding in the youth custody estate and failure to adopt a “child-focused” approach towards young offenders.

It comes after scandal-hit youth jail Medway was judged by Ofsted to be placing children at “unacceptable risk”, with a significant increase in use of force against children, despite efforts to improve conditions since a BBC Panorama investigation four years ago exposed widespread abuse at the facility.

The report found that around 359 incidents involving force were reported in the last six months – of which approximately 115 incidents occurred in September alone – and that staff were still using techniques during physical-restraint incidents that inflicted pain on children, with seven such incidents recorded since January.

Carolyne Willow, director of Article 39, said the rise in serious restraint incidents was “deeply concerning” but the true number of abuses against incarcerated children would be far higher, as flaws in the recording of these incidents and fear of retribution among young people meant many went unreported.

She pointed out that only half of the six councils with child prisons in their area provided information showing how many allegations referred to them were substantiated, indicating a lack of data and auditing that she said “obscures the true picture”.

Ms Willow added: “It is also down to the difficulty children face when reporting abuse within closed institutions – they’re often scared of retribution and being treated less favourably by staff. It is often one child’s word against several members of staff. They know that the odds are they won’t be believed.

“They’re kept in a state of subservience and powerlessness, where grown adults in uniform are allowed to inflict physical and psychological pain. And often they don’t know when something is unlawful and abusive. They think if something is commonplace and is done in public and more than one member of staff is doing it, then that must be the official way.”

She said staff shortages were a “massive issue”, with the institutions operating with the “least number of staff that the state can get away with”, adding: “It creates the most appalling physical environments for children. The government has publicly acknowledged that they’re not fit for purpose.”

Frances Crook, chief executive of the Howard League for Penal Reform, said the charity was “very worried” about child abuse in jails and that the figures “appeared to represent the tip of the iceberg”.

“We intend to do some further work ourselves in the coming months to explore what is going on, and to find out why children and young people are being placed in such dangerous prisons,” she added.

The data on restraint, published in documents released by the Ministry of Justice under FoI laws, show the number of reports made by prison staff under the Serious Injury and Early Warning Signs process – used to record restraint that has resulted in a child having breathing difficulties or other injuries – has increased by 257 per cent in four years.

Of these reports, 28 involved a child having breathing difficulties, 124 had complaints of such difficulties, seven had serious injuries, 11 had a loss of or reduced consciousness and 22 complained of feeling sick.

Responding to the findings, Anna Edmundson, NSPCC policy manager, said there should be clearer and more robust child protection procedures in place, adding: “Many of these children have already experienced abuse and neglect and that complex background is part of the reason they might be detained.

“Despite a long list of recommendations about how these institutions need to change to better protect children, progress is painfully slow and safeguarding still doesn’t appear to be the top priority.”

John Drew, former chief executive of the Youth Justice Board (YJB), said the rise was “very concerning” and that while it was in part attributable to greater awareness of the importance of reporting abuse, it was also the result of a “demoralised prison service, starved of resources and facing a calamitous turnover of staff”.

He continued: “Almost all of the staff working in child prisons are good people doing a very difficult job in circumstances that very few of their critics would be able to do. But until we start spending a lot more money looking after children in custody, these figures will not fall.

“More money for smaller units, which can be nearer to home, and more money for more staff are obvious places to start. A child-focused approach, based on children’s rights, will also make a big difference.

“Listening to children in custody can lead to big differences in attitude, as well as better support for staff, including clinical supervision so that they understand why the children in their custody behave the way they do and how they can be helped.”

A Youth Custody Service spokesperson said: “Staff are trained to resolve conflict verbally and we are clear that restraint should only be used as a last resort, where there is a risk of harm to self or others, and no other form of intervention is possible or appropriate.