More than 25 of the CIA's war-on-terror prisoners were subjected to sleep deprivation for as long as 11 days at a time during the administration of former president George Bush, according to The Los Angeles Times.

At one stage during the war on terror, the Central Intelligence Agency was allowed to keep prisoners awake for as long as 11 days, the Times reported, citing memoranda made public by the Justice department last month.

The limit was later reduced to just over a week, the report stated.