Central Intelligence Agency (CIA) John Brennan
Director of the CIA John Brennan has admitted that some agency officers used 'abhorrent' interrogation techniques REUTERS/Larry Downing

Two Central Intelligence Agency (CIA) psychologists who helped design controversial interrogation techniques of suspected terrorists are to face legal action by the American Civil Liberties Union (ACLU). Former US Air Force psychologists James Mitchell and John "Bruce" Jessen used information from 1960s experiments to create programmes designed to break the will of people suspected of having information about terror attacks.

The methods used by CIA operatives included forms of waterboarding, beatings and sleep deprivation. All have been described as torture and discredited following a 2014 Senate report which found no valuable information had been obtained as a result of their use. Many observers believe the program actually did far more harm than good, harming the US's reputation as the "world's policeman" and fermenting hatred among Muslims in particular.

The case against Mitchell and Jessen can go ahead following assent from Federal Judge Justin Quackenbush from Spokane, Washington State. Three suspects, none of whom were ever convicted of any links to terrorism, are being represented by the ACLU. One of the three, Gul Rahman, was held at a CIA centre in Afghanistan known as "the Salt Pit". Subjected to immersion in cold water and left in darkness he later died from hypothermia.

Another of the men, Tanzanian fishermen Suleiman Abdullah Salim, was held in a CIA prison but was released without charge. Speaking from his village in Tanzania, he told the Guardian he was still haunted by the experience. "You can't sleep, you can't eat, you can't smell. Flashbacks come anytime, so much they make you crazy."

Demonstrators simulate waterboarding at the Justice Department in Washington in 2007 Reuters

Libyan exile Mohamed Ahmed Ben Soud described his experiences to the United Nations Human Rights Council. He is now back in Libya with his family. Held for 18 months in a CIA prison near Bagram, he said the CIA had violated "all international conventions of humanity, morality, and legality".

Ben Soud continued: "The teams of interrogators used violence that exceeded any kind of humanitarian and moral limits. This included slamming us against the walls, slapping in the face, punching in the stomach, pouring ice water on our naked bodies, creating the illusion of drowning several times, and stuffing us in small boxes.

"I was hung by my hands to the ceiling of the room for a day and a half. We were deprived of food as part of a methodical program where they sometimes prevented us from eating for 30 hours. The meals were of poor quality and very limited quantity, lacking any nutritional value. We were deprived of medicine and any medical care."

A lawyer for Mitchell and Jessen said the two defendants were being used as scapegoats for wider failings by the government. "Ultimately the CIA was authorized by the president of the United States to take these actions."