A migrant sex predator who attacked lone women avoided deportation for almost a decade through ‘impermissibly speculative’ human rights judgments about what could happen to him back home, a court has found.

The man, 40, who came to Britain illegally, is finally being deported after lengthy legal wrangles dating back to 2017.

The hiatus continued despite a mental health tribunal concluding the paranoid schizophrenic still posed ‘a serious danger’ to the public after an incident with a knife three years ago.

The Home Office successfully overturned the most recent rulings allowing the man, named only as OSB, to stay on the grounds that if he is deported he may forget his medication, commit further offences and end up in prison in his homeland.

Appeal Court judge Mr Justice Bean said of the most recent previous ruling, by a first-tier immigration tribunal judge and backed by an upper tier panel of judges, said: ‘This is in my view impermissibly speculative.

‘It is not a sequence of events for which the UK can sensibly be held responsible. The consequences which are said to breach Article 3 (which prohibits inhuman or degrading treatment) are too remote.’

The Nigerian national, granted anonymity by the immigration courts and known only as OSB, had committed attempted rapes in 2009.

At Southwark Crown Court later that year, he was convicted of three attempted rapes and kidnapping with intent to commit a sexual offence, and detained in hospital due to his mental condition.

At his sentencing, a judge described the attacks as ‘a terrifying affair’ for the victims and said he would probably have imposed a life sentence had it not been for mental illness.

In the first attack, a 16-year-old girl was dragged into an alleyway where OSB forced her to the ground, pulled down her trousers and underwear before a passer-by intervened.

Two days later, he attacked a second woman from behind on a street at night, trying to pull down her jogging bottoms. She only escaped after defending herself with a glass bottle, injuring his hand.

Just 20 minutes later, he struck again, lifting another woman off her feet and dragging her into an alleyway before she managed to break free screaming.

The Home Office issued a deportation order in February 2017, but what followed was a legal battle involving multiple appeals, judicial reviews, fresh asylum claims and emergency interventions by lawyers.

The dispute dragged on despite medical evidence which showed OSB continued to suffer chronic paranoid schizophrenia but repeatedly stopped taking medication — triggering dangerous relapses.

In 2023, he was returned to hospital after allegedly producing a knife during an incident at supported accommodation where he was living.

Mental health tribunals concluded he still posed ‘a serious danger’ to the public and should remain in secure hospital amid a risk of further violent offences.

Lawyers for OSB claimed that because of his schizophrenia, a return to his homeland would risk inhuman or degrading treatment, breaching Article 3 of the European Convention on Human Rights.

OSB is finally being deported after the Court of Appeal allowed a challenge by the Home Office against a 2024 decision by a first-tier immigration tribunal judge, which had been upheld by an upper tier tribunal.

Lord Justice Bean said: ‘The consequences which are said to breach Article 3 are too remote.’

Allowing the Home Secretary’s appeal, Lord Justice Bean concluded: ‘Nearly ten years after that order was made, it is high time that it was put into effect.’

Both the first tier and upper tier tribunal judges had accepted OSB’s lawyers’ submissions that there was still a ‘high risk’ he would stop taking medication, relapse, commit more serious offences and end up in a Nigerian prison without psychiatric care.

The first-tier judge ruled that such a scenario could lead to ‘a serious, rapid and irreversible decline’ in his mental health and therefore breach Article 3.

Upper tier judges backed the findings, calling them ‘detailed, balanced and carefully reasoned’.

The Home Office appealed, arguing the ruling was wildly speculative and stretched human rights law ‘too far’.

Appeal Court judges found the tribunals had misapplied Supreme Court guidelines by failing to consider whether OSB’s alleged deterioration if he stopped taking medication would amount to ‘intense suffering’ - a key legal threshold.

Lord Justice Bean, sitting with Lord Justice Singh and Lord Justice Baker, said the earlier tribunals built their judgments on ‘too many links in the chain’.

The judges ruled that Britain could not be held responsible for what might happen after deportation.

OSB had no right to be in Britain from the beginning, with court documents showing he arrived in February 2000 using a forged passport.

A bid to remain in the UK was rejected in 2007 and his appeal rights were exhausted by January 2008, yet he remained in the country unlawfully before committing his crimes.

The Home Office issued an initial notice of deportation proceedings in June 2015 – followed by a deportation order in February 2017 – resulting in the prolonged human rights battle, including a deportation attempt in 2019 which failed when his relatives physically stopped him being taken into custody.