The trial of Irish man Ibrahim Halawa in Egypt has been postponed for the 18th time.
Halawa, who last month celebrated his 21st birthday, has spent almost three and a half years in prison.
Amnesty International has said that, based on a thorough review of his case, they have determined that he could not have committed the serious crimes which he was accused of.
He was 17 when he was first detained in August 2013. Last week a group of TDs were in Egypt to call for him to be freed.
The group, who have declared him a Prisoner of Conscience, claim: "He has been imprisoned solely for peacefully exercising his right to freedom of expression and freedom of assembly."
Colm O’Gorman, executive director of Amnesty International Ireland, said: "This young Irish citizen has now been detained for almost three and a half years. In this time, he has experienced unfathomable suffering.
"He has endured eighteen delays in his mass trial and spent 41 long months living in horrendous conditions in an Egyptian prison cell.
"Ibrahim’s ongoing detention is a clear and inexcusable violation of both Egyptian and international human rights law.
"Amnesty International remains gravely concerned for his physical and mental well-being.
"It is long past time that the Egyptian authorities respect international human rights law and allow this young Irish citizen to return home."
Last week, reports emerged that Egyptian President el-Sisi has said that Ibrahim will be released and returned to Ireland upon completion of his trial.
"Though this development might appear encouraging, Ibrahim’s release is dependent on the completion of an unfair judicial process. Today, following the eighteenth postponement, there is no sign that this unfair mass trial will conclude soon," O'Gorman added.
His trial has been rescheduled for February 14.