Secret Ballykelly interrogation centre unveiled
Declassified papers have revealed the existence of an interrogation centre in Ballykelly, County Londonderry, in the 1970s, a human rights group has said.
The Pat Finucane Centre claims the government misled two official inquiries and the European Court of Human Rights over its existence.
The Ministry of Defence said the Ballykelly centre was one of a number "identified" as part of internment.
It said it had "always fully cooperated" with statutory inquiries.
"Following a number of allegations made by some detainees the MoD fully cooperated with all investigations into these matters," it added.
More than 300 people were interned in Northern Ireland in August 1971.
A total of 12 internees were subjected to "deep interrogation".
It is claimed they were subjected to interrogation known as the five techniques.
In a case brought to the European Court of Human Rights by the Irish government against the government in the 1970s, there was no mention of an interrogation centre at Ballykelly.
The Pat Finucane Centre, a human rights advocacy and lobbying group in Northern Ireland, claims the government misled two official inquiries and the European Court of Human Rights over its existence.
Sara Duddy of the Pat Finucane Centre told BBC Radio Foyle they had "spent a lot of time at the National Archives and now we can shed light".
"In these documents there is reference to the centre in Ballykelly," she added.
"There is also reference that the centre was not to be disclosed.
"We think the European court has to examine this again. We have asked the (Irish) department of foreign affairs to examine what they were told at the time.
"We have documents that state that men were expected to stand against a wall for an excess of 49 hours.
"The Pat Finucane Centre had cross referenced this new information with the contents of previous inquiries, such as the 1971 Compton Report and the Parker Report one year later."
The Compton Report looked into alleged use of brutality by security forces in Northern Ireland, while the Parker Report investigated interrogation methods against terror suspects.
The Pat Finucane Centre will give a presentation in the near future in Belfast, presenting the documents along with other declassified government documents on the interrogation of detainees in the 1970s.
The Irish Department of Foreign Affairs is examining the matter.