Amnesty International says it's disgraceful that Ibrahim Halawa continues to be detained in jail in Egypt.
His trial was put back for another week yesterday, after lawyers asked for more time to challenge video evidence relating to other defendants in the mass trial.
The 21-year-old from Firhouse has been in jail almost four years.
Amnesty's Colm O'Gorman says this latest development will hold up the trial even longer.
"Some of the defence lawyers want to challenge video evidence that's been presented by the prosecution.
"From Ibrahim Halawa's perspective, this will be incredibly frustrating because we know that video evidence implicates or identifies only two of the many hundreds of the defendants in the case - and in no way identifies or identifies Ibrahim".