British government ministers sanctioned the use of torture against prisoners in Northern Ireland in the early 1970s.
New documents found by Irish TV station RTE reveal home secretary Merlyn Rees told Labour prime minister James Callaghan this in 1977.
In August 1971 Northern Ireland prime minister Brian Faulkner introduced internment without trial.
A dozen of those arrested were hooded, flown to a secret location and tortured.
In 1976, the European Commission of Human Rights ruled the interrogation methods used were torture.
They comprised lack of sleep and food, hooding, standing for hours at a wall with legs apart and arms high and continuous noise.
In his letter Rees said, “It is my view (confirmed by Brian Faulkner before his death) that the decision to use methods of torture in Northern Ireland in 1971-1972 was taken by ministers.”