Evidence that an exclusive riding academy in Lithuania was used as a secret CIA detention centre has been uncovered by ABC News.
ABC News said its evidence showed the riding academy outside Vilnius was converted into a prison used to interrogate up to eight suspected al-Qaeda terrorists at a time.
"The activities in that prison were illegal," human rights researcher John Sifton told ABC.
"They included various forms of torture, including sleep deprivation, forced standing, painful stress positions."
The property was allegedly bought by a CIA front company.
The CIA built a thick concrete wall inside the riding arena and then a building within the building, which included prefrabricated pods to house the prisoners. The pods could not be seen from the outside.
Intelligence officers were housed next door in a converted stable.
This week, CIA spokesman Paul Gimigliano told the news organisation: "The CIA's terrorist interrogation programme is over. This agency does not discuss publicly where detention facilities may or may not have been."
The riding school prison was believed to have been one of eight such facilities around the world.