Halawa: 'It feels like 1,000 years in jail'
Irishman Ibrahim Halawa said the 1,000 days he has spent in prison in Egypt have felt like 1,000 years.
In a letter to his family, he said he is suffering and other prisoners have taken their own lives.
The 20-year-old was arrested in Cairo during political protests in 2013 and he is currently awaiting trial and a potential death penalty.
His family held a demonstration in Dublin yesterday to mark the 1,000 days he has spent in prison.
His sister, Somaia Halawa, shared a letter he sent the family last week.
"One thousand days with 1,000 different stories. Sadly not the type of joy, laughter and smiles. But rather the type full of suffering, pain, torture, tears, abuse, suicide and death," he wrote.
"One thousand days that have felt like 1,000 years, not only for me but for hundreds behind bars."
Somaia Halawa said she wants to see more assertive action to free her brother.
Amnesty International's director Colm O'Gorman said the organisation conducted a review of the prosecution evidence and concluded that Mr Halawa could not have committed the crimes with which he has been charged.
His mass trial has been delayed 13 times and is now due to take place on June 29.
The Department of Foreign Affairs said every effort is being made to secure his release.