The Central Intelligence Agency (CIA) has practiced sleep deprivation to more than 25 terror suspects during the Bush administration, a report says. The Justice Department memos released last month showed that at one point, the agency was allowed to keep prisoners awake for as long as 11 days, The Los Angeles Times reported late Saturday. However, the limit was later reduced to just over a week, the paper said. Sleep deprivation method, which the CIA fought hardest to keep, has been described as one of the most important elements in its interrogation program used to help break dozens of suspected terrorists. The prisoners had their feet shackled to the floor and their hands cuffed close to their chins, said the report citing Justice Department memos. Detainees were clad only in diapers and not allowed to feed themselves. A prisoner who started to drift off to sleep would tilt over and be caught by his chains. When detainees could no longer stand, they could be laid on the prison floor with their limbs "anchored to a far point on the floor in such a manner that the arms cannot be bent or used for balance or comfort," according to a May 10, 2005, memo. A Red Cross report on the CIA program in 2007 said detainees' wrists and ankles bore scars from their shackles. President Barack Obama, who calls waterboarding, sleep deprivation and other coercive practices torture, prohibited the methods in January. A task force however is reviewing the use of sleep deprivation along with other harsh interrogation methods the agency might employ in the future. Because of its effectiveness -- as well as the perception that it was less objectionable than waterboarding, head-slamming or forced nudity -- sleep deprivation may be seen as a tempting technique to restore, The Times concluded.