Several human rights defenders and two foreign nationals were also detained
Foreign Affairs Minister Simon Coveney has hit out at the detention of Amnesty International Executive Director Idil Eser in Turkey.
Ms Eser and nine others, including seven human rights defenders and two foreign nationals, were arrested in Istanbul on Wednesday.
Mr Coveney said: "While the exact circumstances of their detention remain unclear, the arrests mark a profoundly disturbing development in the ongoing trends we are seeing in Turkey in respect of human rights, democracy, rule of law and freedom of expression.
"Ms Eser and, indeed all those detained, must be granted access to their lawyers and full due process, including the presumption of innocence.
"I call on the Turkish authorities to recognise and respect the crucial role that NGOs, including Amnesty International, play in a functioning, democratic society."
The group were detained during a digital security and information management workshop in Büyükada, Istanbul.
Two foreign trainers, a German and a Swedish national, were also detained.
The whereabouts of Ms Eser and the others detained are currently unknown.
Ms Eser and the other detainees are understood to have been denied access to lawyers - which police are entitled to do for 24 hours - and the right to contact a family member, which must be granted immediately.
Their arrests come less than a month after the arrest of Taner Kiliç, chair of Amnesty International Turkey, and 22 other lawyers in Izmir in June.
Amnesty International Ireland say the group arrested is being investigated for membership of an armed terrorist organisation.
Colm O’Gorman, executive director of Amnesty International Ireland, said: "The absurdity of these accusations against Idil Eser and the nine others cannot disguise the very grave nature of this attack on some of the most prominent civil society organisations in Turkey.
"Their spurious detention while attending a routine workshop was bad enough: that they are now being investigated for membership of an armed terrorist organisation beggars belief.
"If anyone was still in doubt of the endgame of Turkey’s post-coup crackdown, they should not be now.
"There is to be no civil society, no criticism and no accountability in Erdogan’s Turkey.
"If world leaders meeting at the G20 fail to stand up for Turkey’s beleaguered civil society now, there may be nothing left of it by the time the next summit comes around."
A state of emergency has been in operation in Turkey since a failed coup attempt on July 15th 2016 - which have seen some 140,000 public servants, journalists and academics dismissed, detained or arrested.