DOCUMENTS revealing the whereabouts of a secret internment interrogation centre at Ballykelly in 1971 have been uncovered.
The details were uncovered by the Pat Finucane Centre in new declassified documents.
On the morning of August 9 1971, British soldiers swept across the north interning around 350 nationalists without trial.
The move was the unionist Stormont's response to the growing civil unrest.
However, the policy backfired causing huge resentment in nationalist communities.
Based on outdated RUC intelligence files, internment brought no reduction in violence levels.
Its introduction and the subsequent torture of 12 internees in particular hardened nationalist attitudes towards the state.
Now newly declassified documents have revealed a secret British army interrogation centre was based at Ballykelly in Co Derry.
According to a spokesman for the Pat Finucane Centre (PFC), the whereabouts of the centre was deliberately withheld from two inquiries and from the European Court of Human Rights.
The spokesman said: "A British lieutenant colonel reported: 'It was very important to keep secure the existence and location of the centre at Ballykelly where the 12 detainees in question had been interrogated. It was not publicly known that this centre existed as well as others which were known.'"
The PFC has notified the Department of Foreign Affairs in Dublin of its discovery and is preparing a sub-mission to the Committee of Ministers in Europe.
Other documents detail how the British government decided to settle compensation cases out of court rather than be accused of human rights abuses, the centre said.
As part of Belfast's Feile an Pho-bail, the PFC will be joined by four of the original torture victims at a presentation based on the declassified documents.
The Northern Ireland Office last night declined to comment on the PFC allegations.