Irish citizen Ibrahim Halawa was transferred between prisons in Egypt in recent days without the knowledge of the Irish Government or his family.
The 20-year-old from Firhouse in Dublin is to stand trial in Egypt alongside 419 other defendants on charges that include terrorism, murder and the use of explosives.
He was arrested in Cairo in August 2013 and since then he has been held in prison without trial.
He was detained at the al-Fateh mosque during protests against the former Egyptian president, Mohamed Morsi.
His trial has been adjourned 13 times to date. A new trial date has been set for June 26th.
Mr Halawa's sister Somaia told RTÉ Radio on Tuesday that the last contact his family had had with him was a week earlier at the Tora Prison, but he was no longer there and they were unaware of his whereabouts.
Initially, the Department of Foreign Affairs said it believed Mr Halawa was at the Tora Prison facility, but following further investigation it established he had been transferred to the the Wadi el Natrun prison on Monday.
“Following contradictory reports earlier today, it has now been confirmed by the Egyptian authorities in Cairo and by their embassy in Dublin that Mr Halawa was transferred to the Wadi el Natrun prison yesterday,” the department said.
“Irish diplomats in Egypt will make another consular visit to Mr Halawa in the coming days.”
‘Unacceptable’
Earlier, Mr Halawa’s sister Somaia said it was unacceptable that her brother was moved without the Egyptian authorities informing the Irish Government and his family.
“He was moved without us being informed and without his lawyer being informed,” she said.
“What’s worrying is that he has been moved several times without us being informed so we don’t know where my brother is.
“This lack of information and communication shows the Egyptian authorities don’t respect that Ibrahim is an Irish citizen.”
She said the Egyptian authorities had misled the Department of Foreign Affairs and called on the Government to adopt a “harsher” approach in its efforts to secure his release.
“This needs a different type of negotiation and a different type of approach,” she said.
“When are the Irish Government going to realise they need to change their strategy and that a harsh strategy needs to be taken towards the Egyptian authorities.”
