A young offenders institute (YOI) is set to shut down and be reopened as an adult prison later this year.

Troubled HMP Cookham Wood has faced criticism in recent years for high levels of violence among inmates and appalling conditions were uncovered.

Now, the site in Borstal, near Rochester, will be closing before it reopens again in the summer to house adult criminals.

Young inmates will be moved to different sites, including a new “Secure School” at an adjacent site which the Ministry of Justice (MOJ) is describing as “a ground-breaking new approach to youth custody that will place education and wellbeing at its heart”.

The YOI has a capacity of 188 prisoners, but it is thought the real number of inmates is under half that figure.

Prisons and Youth Justice Minister Edward Argar said: “We are transforming the provision of custody for young offenders and over the last decade we have seen a significant fall in young people entering custody.

“Those housed within our youth estate often have very complex needs and have committed violent crime, and Cookham Wood is no longer serving their needs.

“This is why we are announcing plans to move them to sites to offer better support and help turn their backs on a life of crime as well as increase capacity within our adult male estate.”

In April last year, Cookham Wood was issued an urgent notification by His Majesty’s Inspectorate of Prisons over concerns around the standard of care being provided to young offenders with complex needs.

It has since been closely monitored, but the MOJ says it’s become clear further improvements needed cannot be delivered at the scale required in an acceptable time frame.

Over the last decade, the number of children in custody has fallen by nearly 70%.

The most recent report on the prison said there was a lack of progress at the site where violence is rife and “demoralised” prison staff are leaving in their droves.

Resignations at Cookham Wood were on the increase and an inspection last April found problems across the board, including widespread weapon making and staff “reluctant” to search inmates or their dirty cells for fear of recourse.

Conditions were also slammed with around a quarter of the 79 boys there kept completely separated from other offenders, with some being locked away almost 24 hours a day – and two for more than 100 days to “manage conflict” between the inmates.

Speaking at a council meeting in January, Tory leader, Cllr Adrian Gulvin, expressed concern that drugs were not mentioned anywhere in the report and said that a resident within his ward, who did not want to be named, had previously told him that drugs were basically allowed because it meant the inmates were easier to deal with.

He said: “It’s not mentioned in the report at all, which is that there’s a huge drug problem.

“The accusation was almost made that staff were allowing the drugs to circulate because that kept the children quieter.

“While they were drugged up to the eyeballs they were easier to control was virtually what was said.”

Councillor Lauren Edwards, who represents Rochester East and Warren Wood, said: “The deteriorating situation at Cookham Wood has been a growing concern – and it is right to recognise that measures put in place to make improvements haven’t worked and that for the safety of all placed and working there, action needed to be taken.

“However, I am concerned that the Ministry of Justice are looking to run the facility for adults, sneaking in an additional prison by the backdoor, with no consultation with the public, because they have failed to build enough prison spaces over the last 14 years.

“There are only around 900 prison places left available and this shows how badly the Conservatives have failed to manage the criminal justice system.”

Labour councillor Alex Paterson, who represents Rochester West and Borstal, added: “The purpose of youth justice is not simply to punish wrongdoing but to divert the next generation of offenders away from criminal activity.

“Without access to education and purposeful activity that function is severely limited, so it is right that children and young people being held at Cookham Wood are found accommodation which is more appropriate to their needs."

Deputy leader of the Conservatives, Councillor George Perfect, said: “The decision taken today by the Secretary of State in relation to HMYOI Cookham Wood is the right one.

“As outlined at January’s Overview and Scrutiny meeting, we have had concerns for some time about the pace of change at Cookham Wood.

“Today’s decision will ensure that the children and young people involved are moved to safer environments whilst also assisting the pressure currently facing capacity within the adult prison estate.”