Producers of a reality TV show claim to have recreated torture techniques used at US detention camp Guantanamo Bay.
The US government has denied using torture at the camp
The Guantanamo Guidebook was made by Channel 4 using declassified documents about the US camp, producers said.
The methods used on seven volunteers in the show included religious and sexual humiliation, forced nudity, sleep deprivation and extreme temperatures.
The US government has denied using torture at the camp in Cuba, where many detainees are held without charge.
The show's volunteers - who were told what they would go through - were locked in a warehouse with cages, interrogation rooms and surveillance equipment for 48 hours.
One left after seven hours because of the onset of hypothermia and another two vomited during their "detentions".
Channel 4's head of news and current affairs, Dorothy Byrne, said: "The use of torture or of information gained through torture has been justified as essential in the war against terror.
"This season of programmes challenges viewers to watch torture techniques we know are used in Guantanamo."
The show will be broadcast later this month.
A documentary by Clive Stafford Smith, the first British lawyer allowed into Guantanamo, will be among three films shown about torture on Channel 4.