A teenage boy has been found dead at a jail near Rochester criticised last year for high levels of violence and a significant use of weapons by inmates.

The boy was discovered unresponsive in his cell at Cookham Wood Young Offenders’ Institution at around 6.40am on Saturday.

The Youth Justice Board said: “The cause of death will be formally determined by inquest but, at the present time, we have no indication that the young person took their own life or that the circumstances were suspicious.”

A Prison Service spokesman said: “Staff attempted resuscitation and paramedics attended but he was pronounced dead at approximately 8am. His next of kin have been informed.

“Every death in custody is a tragedy and we always seek to improve our procedures for caring for prisoners, including young offenders, where possible.”

Significant use of weapons by inmates and “high and rising” levels of violence at the jail were revealed in a report by Her Majesty’s Inspectorate of Prisons (HMIP) published in October.

Some 35 weapons were found in a lockdown, and 169 acts of violence were recorded during the six months before the inspection, up from 130 at the previous inspection.

The Howard League for Penal Reform said at the time that assaults and serious injuries had “become the norm” at the jail and cuts had pushed the prison system to “breaking point”.

The National Offender Management Service (NOMS) said the governor was “actively tackling” violence in the jail, staff were being given extra training in behaviour management and use of force had been cut.

Built in the 1970s, Cookham Wood YOI holds up to 131 15 to 18-year-olds who have been sentenced or are on remand.

The Prison Service said: “As with all deaths in custody there will be an investigation by the independent Prisons and Probation Ombudsman.

“Additionally, as he was under the age of 18, there will be a serious case review commissioned by the local safeguarding board.”

A spokesman for the Youth Justice Board said: “We offer our condolences to the family for their tragic loss.

“The relevant agencies are already undertaking inquiries into the circumstances and cause of death, and we want to ensure that any findings are acted on as they arise.”