Ministers were warned for months about serious failings at a struggling prison before a convicted sex offender was released by mistake, it has emerged.

The error at HMP Chelmsford, in Essex, saw Hadush Kebatu – an Ethiopian asylum seeker jailed for sexually assaulting a 14-year-old girl and a woman – freed when he should have been handed to immigration officers.

Kebatu was later tracked down and deported, but the blunder has raised fresh questions about oversight and staffing in the prison system.

The Independent Monitoring Board repeatedly warned of problems at Chelmsford, citing ‘poor communication’ and ‘frequent administrative errors’.

Its annual report, published earlier this year, described chaotic release procedures and overstretched staff struggling to manage complex cases.

Despite those warnings, the 38-year-old was mistakenly released while awaiting transfer to immigration detention ahead of his planned deportation back to Ethiopia.

Incredibly, it later emerged how the ‘confused’ migrant tried to return to the prison multiple times, only to be turned away and directed to the railway station by staff where he then travelled to London.

Justice Secretary David Lammy called the incident ‘appalling’ and blamed ‘human error’ after a single staff member was suspended. 

The error at HMP Chelmsford, in Essex, saw Hadush Kebatu (pictured) - an Ethiopian asylum seeker jailed for sexually assaulting a 14-year-old girl and a woman - freed when he should have been handed to immigration officers

The error at HMP Chelmsford, in Essex, saw Hadush Kebatu (pictured) – an Ethiopian asylum seeker jailed for sexually assaulting a 14-year-old girl and a woman – freed when he should have been handed to immigration officers

Kebatu was later tracked down and deported, but the blunder has raised fresh questions about oversight and staffing in the prison system

Kebatu was later tracked down and deported, but the blunder has raised fresh questions about oversight and staffing in the prison system

But the Prison Officers’ Association said the case reflected wider system failures rather than one individual’s mistake.

The suspended member of staff was responsible for going through the paperwork to ensure that the right prisoner was being released under the right conditions.

However, the manager was checking paperwork that had already been processed by more senior staff, The Guardian reports.

The Ministry of Justice declined to explain whether the department had addressed failings raised in the report because of the ongoing inquiry.

According to the IMB report, HMP Chelmsford’s release processes were examined after receiving a complaint from an ‘extremely stressed’ vulnerable prisoner who, a few hours before release, had been given no information about where he might live or how to contact his probation officer.

‘On investigation, we discovered a litany of issues and errors that had led to this situation: the failure of officers to collect the prisoner for his release process briefing; a re-arranged release process briefing cancelled because it clashed with a knife awareness course; and a mix-up over release dates.

‘While we must assume these instances are rare, we would urge those involved to update their processes to stop prisoners “falling through the cracks”,’ the report said.

Kebatu, who arrived in the UK on a small boat, was eventually arrested in north London on Sunday morning after a two-day manhunt.

He was pictured being detained by four officers inside Finsbury Park, with Prime Minister Sir Keir Starmer vowing he ‘will be deported’.

The Home Office has now confirmed Kebatu was removed on a flight to Ethiopia on October 28 and arrived on October 29.

Home Secretary Shabana Mahmood said: ‘Last week’s blunder should never have happened – and I share the public’s anger that it did.

‘I would like to thank the police for rapidly bringing Mr Kebatu into custody and the public for their vigilance.

‘I have pulled every lever to deport Mr Kebatu and remove him off British soil. I am pleased to confirm this vile child sex offender has been deported.

‘Our streets are safer because of it. If you come to this country and commit crimes, we will remove you.’

A minister said it was ‘unacceptable’ that a prisoner had been released without checks being done to ensure that was correct.

It was put to border security minister Alex Norris on Sky News that the situation ‘beggars belief,’ to which he replied: ‘It’s unacceptable.

‘It’s why were so angry about it, it’s why we’ve put those changes in.’