Declassified British documents show there was a secret interrogation center in Ballykelly, Co Derry in the early 1970s during the Troubles.

The Pat Finucane Center has discovered the declassified files which show the location of the interrogation center at Ballykelly was a closely kept secret.

RTÉ reports that in 1971 twelve internees were subjected to violent ill-treatment, which led the Irish government to take a case on their behalf to the European Commission of Human Rights.

The papers reveal that the 12 men, arrested as part of the internment of 350 people on 9 August 1971, were subject to deep interrogation under the five techniques system the European Commission has called ‘torture’. The techniques are wall-standing, sleep deprivation, hooding, starvation and white noise.

The interrogations were carried out by the RUC overseen by the British army.

In 1976, the European Commission found the interrogation of the 14 men amounted to “inhumane treatment and torture.” In January 1978, the European Court lessened this judgment to “inhuman and degrading treatment.”

According to the Pat Finucane Center a British lieutenant colonel reported: "It was very important to keep secure the existence and location of the center at Ballykelly where the 12 detainees in question had been interrogated. It was not publicly known that this center existed as well as others which were known."

Claims suggest London misled two official inquiries and the European Court of Human Rights about the existence of the center.

Speaking on RTÉ’s Morning Ireland, Sarah Duddy of the Pat Finucane Center said the documents had uncovered the use of techniques such as hooding, sleep deprivation, diet restrictions, white noise and other methods on detainees at the Derry center.

“The documents reveal a lot of things,” Duddy told RTÉ’s Morning Ireland.

“They reveal the existence of the center as well as the lengths that the British Government went to to keep the existence of the center concealed.

“One document says “it’s very important to keep secure the existence and location of the center where the 12 detainees were interrogated secret.”

“That document was circulated while an inquiry was taking place. So, even while the inquiry was going on, the British Government were adamant that they had to keep the location and existence of the center secure.”

Duddy said the Center had cross referenced the findings of previous inquiries, such as the 1971 Compton Report and the Parker Report one year later, which probed allegations of brutality in Northern Ireland.