Criminals have been released early by mistake or held illegally beyond their release date in “appalling conditions” inside a chaotic and squalid prison, a watchdog has warned.
The chief inspector of prisons Charlie Taylor has issued an urgent notification to the government over the state of medium security HMP Pentonville.
The overcrowded Victorian jail in north London, where most prisoners share cells designed for one person, is infested with mice and cockroaches.
Inspectors discovered 10 inmates in the Category B jail had been released early “in error” between July 2024 and June 2025 because staff “failed to calculate sentences accurately”. The prison holds a wide range offenders, including some jailed for violent crimes.
A further 130 inmates – 20 per cent of those eligible for release – had been held illegally after their release date in the last six months.
In a letter to justice secretary Shabana Mahmood, the chief inspector said arrangements for new prisoners’ first night at the north London jail and induction were “chaotic and even frightening”.
Men were held in dirty cells missing bedding, furniture, telephones and pillows, the watchdog said, while the majority of prisoners were locked in their cells for more than 22 hours a day.
Inspectors took emergency action after they found oversight of prisoners at risk of suicide and self-harm was “shockingly poor”, with one prison officer found asleep when they were supposed to be monitoring at-risk prisoners.
Two were found reading books and another was “completely absent”, despite three self-inflicted deaths at the prison in 2025.
Mr Taylor said: “Pentonville is an overcrowded, inner-city, Victorian prison with a record of poor performance over many years.
“Too many of its staff have become disillusioned about the possibility of improvement or their capacity to affect change. Yet many of its shocking failures are firmly within the control of leaders.”
A survey of prisoners also revealed 44 per cent felt unsafe at the time of inspection, which is the highest figure recorded during Mr Taylor’s tenure as chief inspector.
Pentonville is the tenth prison to be issued with an urgent notification since November 2022, following Exeter, Cookham Wood Young Offender Institution, Woodhill, Bedford, Wandsworth, Rochester, Manchester and Winchester prisons.
The Howard League for Penal Reform described the findings as a “new low” for the prisons system.
Andrew Neilson, director of campaigns, said: “The details emerging from this inspection are appalling and outrageous, and they represent a new low for an overcrowded and under-resourced public service that stands on the brink of collapse.
“While the government inherited a dire state of affairs in prisons, it has had more than a year to bring about change. As report cards go, such a dire account of dysfunction in Pentonville instils little confidence that ministers have a grip of the situation.”
Pia Sinha, of the Prison Reform Trust, said the damning report must serve as a rallying cry for action.
“Prisoners illegally held after they should have been released, or others released early in error, further undermine effective sentence planning and erode public confidence,” she added.
“This urgent notification must be a rallying cry for immediate action – fix the failing infrastructure, improve staff training, and treat prisoners with dignity.”
Prisons minister Lord Timpson said: “This is a deeply concerning report and reflects the crisis that has gripped too many of our prisons for far too long.
“Yesterday, I visited HMP Pentonville and met with staff. The team is already working to urgently address the concerns raised by the Chief Inspector. We will publish an action plan in the coming weeks to support them in these efforts.
“This Government will end the chaos we inherited in our jails. We are building 14,000 new prison places and reforming sentencing so our jails reduce reoffending, cut crime, and keep victims safe.”
