A detainee at a CIA "black site" was left with permanent brain damage after agents used him as a living doll to teach trainee interrogators how to torture, declassified documents have revealed.
Ammar Al-Baluchi - a Pakistani 9/11 suspect still being held at Guantanamo Bay - was routinely and repeatedly tortured by CIA agents while at a secret facility north of Kabul, Afghanistan known as "Cobalt".
Details of the methods used on Baluchi - which date back to 2008 - were revealed in documents declassified on Thursday.
