A legal challenge by a man with alleged links to Islamic terrorism aimed at preventing his deportation has opened before the High Court.

The man, whose identity and nationality cannot be published by court order, is “at serious risk of inhuman and degrading treatment” if deported, his counsel Michael Lynn SC said.

On his return he would be detained at a secret location in his home country where he would be “incommunicado”, counsel said when opening the case before Mr Justice Richard Humphreys.

The man, aged in his 50s and living here for some years, claims he is at risk of being tortured and suffering inhuman and degrading treatment if returned to his native country due to his political views.

Mr Lynn, with David Leonard, instructed by solicitor Gavin Booth of the law firm KRW, said deportation of the man would breach both EU law and article 3 of the European Convention on Human Rights.

The Refugee Appeals Tribunal, which considered the man’s application for subsidiary protection, found he would be at risk of serious harm in the form of torture or inhuman and degrading treatment or punishment if returned to his native country.

The Minister, represented by Remy Farrell SC and Sinead McGrath, denies the man’s claims her decision is flawed or involves an error in law. The court heard the man was previously jailed for terrorism-related offences in another jurisdiction.The man denies he is or ever was involved in terrorism.

The hearing has been adjourned to a date next month.