The Minister for Foreign Affairs has expressed his 'deep concern' about the continued detention of Irish teen Ibrahim Halawa.

The 19 year old was due in court in Egypt earlier, but his trial was postponed for a third time.

Charlie Flanagan says Irish diplomatic officials were at the hearing, and are treating Ibrahim's case as a priority. A statement from the Department of Foreign Affairs said Mr Flanagan expressed 'his deep concern about the continued detention of Irish citizen Ibrahim Halawa.'

"I am very disappointed that today’s postponement represents another delay in Ibrahim’s long-running case,” Mr Flanagan said.

"Diplomatic officers at the Irish Embassy in Egypt, including the Ambassador, have been treating this case as a priority and have visited Ibrahim on over thirty occasions since his detention began, and attended today’s hearing.

“We continue to highlight the critical importance of due process in this case. It is the Government’s strong view that Ibrahim should not be tried as part of a group trial involving a large number of defendants,” he added.

The Dubliner, who is facing charges including murder, attempted murder and disturbing public order, has been in prison since August 2013.

Executive Director of Amnesty International Ireland Colm O'Gorman says he is gravely concerned that Halawa will now be unable to receive a fair trial in Egypt.

“There’s now little prospect that Ibrahim can be guaranteed a fair trial in Egypt,” he said.

“We’ve examined in great detail the background to the case and the evidence against Ibrahim and concluded that he is innocent of all charges and is a prisoner of conscience and is being detained purely for exercising his right to freedom of expression and demanding his immediate and unconditional release by Egyptian authorities.”

Dubliner Ibrahim Halawa (19) has been in custody since August 2013 - when he and his three sisters were detained in the capital city. His sisters were freed after three months.

The trial was due to start today but has been postponed until February.

His sister Somaia Halawa says her family, who are in Cairo for the trial, did not get to see her brother today.

A candlelight vigil was held outside the Egyptian embassy in Dublin last month, to mark Mr Halawa's 19th birthday.