The trial of Ibrahim Halawa has been postponed for the twentieth time in Egypt.

The 21-year-old Dublin man has been detained by Egyptian authorities in Cairo since he was arrested at a protest in August 2013.

This is the twentieth time the mass trial, involving more than 400 other defendants, has been adjourned.

It was adjourned until 5 April.

Minister for Foreign Affairs Charlie Flanagan has said he was "disappointed and frustrated" by the delay.

"Ibrahim has now spent more than 1,300 days and nights in an Egyptian prison cell without having been convicted of any crime. This is a source of great concern to the Irish Government."

The Government announced yesterday that it is to send an independent medical expert to examine Mr Halawa.

Mr Halawa is in poor health and on hunger strike, according to his family.

Ireland's Ambassador in Cairo Damien Cole was in court to observe the proceedings.

He said there were a number of witnesses called and cross-examined at the hearing, and petitions from defence lawyers were considered, according to Mr Flanagan's statement.

The panel of judges also ordered that a further medical examinations should be undertaken in respect of Mr Halawa.

Amnesty International has condemned the latest postponement of the trial.

"This young Irish citizen has been through a horrific experience. He's been imprisoned without trial for almost four years and endured 20 trial delays.

"We reiterate our call on the Egyptian authorities to drop all charges against Ibrahim and to order his immediate and unconditional release."