In a new Human Rights Watch (HRW) report released Monday, two former CIA detainees described previously unreported torture techniques used in secret U.S. prisons overseas, shedding new light on the program the government fought for years to keep hidden.

Ridha al-Najjar, 51, and Lotfi al-Arabi El Gherissi, 52, both Tunisian men recently repatriated after being in CIA custody for 13 years without charge, independently described being threatened with a makeshift electric chair, deprived of sleep, subject to multiple forms of water torture, chained by their wrists to the ceilings of their cells for extended periods of time, and severely beaten.

The executive summary of the U.S. Senate Intelligence Committee’s still-classified torture report makes no mention of electric chairs.

HRW writes of El Gherissi’s experience:

He said the chair was made of metal, or perhaps iron. It had clips with wires attached to it intended to be fit on fingers, and a helmet with wires. His description suggested something makeshift, attached to a pipe that came out of a wall. His interrogators put him in the chair and threatened to use it on him unless he gave them more information, though they did not. He said this terrified him and he was trembling. The room also had a board that they threatened to put him on, but never did. He said he understood that water would be used on him while he was on the board.

Al-Najjar separately recounted similar treatment:

It was made out of metal or iron, had plugs attached to wires for fitting on fingers, and a headset with wires. The description suggested make-shift apparatus, attached to a wall pipe. His U.S. interrogators threatened during interrogations to use the chair on him, but never actually did. The room also contained other instruments used for torture, including a board that he believes his interrogators used on him on various occasions for different types of water torture, and a coffin in which they threatened to place him.

“These terrifying accounts of previously unreported CIA torture methods show how little the public still knows about the U.S. torture program,” said HRW senior U.S. national security counsel Laura Pitter.

The most abuse took place at a facility known as Cobalt, a site in Afghanistan, which al-Najjar and El Gherissi called the “Dark Prison.” Other detainees have referred to it alternately as the Dark Prison or the “Salt Pit” as well. Al-Najjar recounted his interrogators at Cobalt “threatening the ‘well-being of his family,’ using ‘sound disorientation techniques,’ denying him sleep using round-the-clock interrogations, depriving him of any ‘sense of time,’ keeping him in ‘isolation in total darkness; lowering the quality of his food,’ using cold temperatures, playing music ’24 hours a day, and keeping him shackled and hooded.'”

A CIA cable issued September 21, 2002 described him as a “clearly broken man” who was “on the verge of a complete breakdown.” He remained in CIA custody for another 13 years.

Both men were set free in 2015 with no compensation or support from the U.S. or Tunisian governments, which violated international human rights law, HRW said—particularly the International Covenant on Civil and Political Rights and the Convention Against Torture, both of which the U.S. has ratified. Under those laws, “governments have obligations to ensure the right to an effective remedy for victims of serious human rights violations, including torture and other ill-treatment,” the human rights group wrote. “Although these violations did not take place in the United States, they occurred while the individuals were under the effective control of U.S. security forces.”

Today, al-Najjar and El Gherissi live with their families in Tunisia in destitute conditions, struggling with severe trauma. Al-Najjar, who said his hips, ankle, and back were broken in detention, told HRW that he is still suffering from damage to several internal organs, as well as his ear. “My sister has five kids,” he told Pitter. “I am the sixth.”

El Gherissi lives with his family in a house that has no doors or full roof. He shares a bed with his elderly mother and cannot afford to see a doctor.

Pitter continued, “The release of these two men without the U.S. providing any assistance or redress for their torture and suffering also shows how much the U.S. still needs to do to put the CIA torture program behind it.”