Shawn Sullivan, 43, claimed sending him back to the States would mean he could be held under a “civil commitment order” that would leave him no hope of release.

And senior judges want to know that he will NOT be placed on a controversial sex offenders treatment programme if he goes back.

The judges, sitting at the High Court in London, said ordering Sullivan to be detained in Minnesota could lead to a real risk of “a flagrant denial” of his human rights.

Sullivan is accused of raping a 14-year-old girl and sexually molesting two 11-year-olds in Minnesota between 1993 and 1994.

He left the US as prosecutors filed charges against him and was later found to be living in Ireland.

He then came to London using an Irish passport, with his name spelt in Gaelic as O’Suilleabhain.

While living in Ireland, he was convicted of sexually assaulting two 12-year-old girls and given a suspended sentence.

He has been described as one of America’s most wanted alleged sex criminals and was arrested in London in 2010.

Mr Justice Eady said the risk of a flagrant denial of human rights was “more than fanciful”.

Sullivan is appealing against a decision of district judge Howard Riddle at Westminster Magistrates’ Court in December 2010 that there was no legal reason why extradition should not go ahead.

He is also challenging the Home Secretary’s decision in February last year ordering his removal.

from 2011