Former National Security Agency contractor Edward Snowden said Wednesday that the United States had committed "inexcusable crimes" during its torture programme detailed by a US Senate report.
Speaking via videolink at a Paris conference organised by pressure group Amnesty International, Snowden -- who exposed secret NSA documents -- said he was "deeply saddened and to a great extent angered by what I read."
"The Senate investigation and the report they have released is extraordinary for a number of reasons... The things we did as a result of this programme are inexcusable crimes," added Snowden.
The US Senate said in a report published on Tuesday that CIA torture of Al-Qaeda suspects was far more brutal than acknowledged and failed to produce useful intelligence.
Detainees were beaten, waterboarded -- some of them dozens of times -- and humiliated through the painful use of medically unnecessary "rectal feeding" and "rectal rehydration."
"We saw individuals who actually lost their lives as a result of detention, as a result of the treatment they received under the torture programme," Snowden said.
"They died after being chained to a concrete floor in an unheated room, half-naked."
Snowden also took aim at Washington's decision not to prosecute those involved.
"If the US can allow its officials to torture and not hold them to account, what does this mean for other more totalitarian states, in Asia and in Africa and elsewhere around the world?" he asked.
"These are things that leave a stain on the moral authority of the United States government and if we do not prosecute and hold them to account, we cannot move forward as a society."
Snowden is wanted by the United States on espionage charges after leaking documents revealing mass US surveillance activities.
The fugitive was granted asylum in Russia, where he has a three-year residency that allows him to travel abroad.
He said he was "doing quite well" in the Russian capital.
"I live an ordinary life. I ride the Moscow underground like everyone else," he said.