Ibrahim Hallawa is enduring horrific conditions in prison in Egypt, according to his barrister.
Mr Halawa, who is from Dublin, was arrested by the Egyptian army as he took refuge in a Cairo mosque while Muslim Brotherhood protesters staged a "day of refuge" outside in August 2013.
The 20-year-old has spent more than 1,000 days in prison.
Katie O'Byrne said Mr Halawa is facing a verdict and sentence on 29 June along with 493 other prisoners even though there has been no substantive trial and no substantive evidence presented by the Egyptian authorities.
She said the legal team does not believe that evidence exists.
Regarding allegations of crucifixion and men being hung from basketball hoops, as outlined in a letter from Mr Halawa smuggled out of the prison, she said there is independent verification of such events from videos smuggled out and from other former prisoners.
She said her client was arrested by an unelected regime while at a protest about the overthrowing of a democratically-elected government and he was protesting in the name of democracy.
She said he has been declared a prisoner of conscience by Amnesty International.
Ms O'Byrne also said the legal team has not been able to take proper instruction from Mr Halawa.
