Extraditing a UK-based terror suspect to an American "supermax" high security prison would constitute "inhuman or degrading treatment", the European court of human rights (ECHR) has ruled.

The Strasbourg court barred the removal of Haroon Aswat, whose nationality is unknown, from Broadmoor psychiatric hospital to the US on account of his severe mental illness.

Aswat, who suffers from paranoid schizophrenia, has been indicted in the US as a co-conspirator in a plan to establish a jihad training camp in Oregon.

He was arrested in 2005 in Britain following a request from US authorities for extradition. His lawyers have resisted his removal since then in a series of appeals.

Although in other extradition cases the ECHR had not found that conditions in ADX Florence in Colorado (a "super-maximum security" prison) were unacceptable, it deemed that Aswat's case was different because of the severity of his mental health condition.

In its judgment, the court said that it had given "full consideration to the submissions of the US department of Justice … and observed, in particular, that it could not be determined with certainty in which detention facility or facilities Mr Aswat would be placed if extradited to the USA, either before or after trial.

"It was also unclear how long he might expect to remain on remand pending trial. As for his detention following a possible conviction … although Mr Aswat would have access to mental health services regardless of which prison he was be detained in, his extradition to a country where he had no ties and where he would face an uncertain future in an as yet undetermined institution, and possibly be subjected to the highly restrictive regime in ADX Florence, would violate article 3 of the convention."

Article 3 of the European convention on human rights prohibits inhuman or degrading treatment. Last year the Strasbourg court allowed the extradition of Babar Ahmad and four other suspects to US federal supermax prisons where inmates can spend 22 or 23 hours a day in solitary confinement.

guardian.co.uk © Guardian News and Media 2013

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