What is "tube torture"?
I saw this term from CNN, but can't figure out the meaning.
Perhaps this is what you are talking about.
"The Applicant states that he was present during the questioning and torture of Norman Choane. He took part in the torture, having been instructed by Lieut Landman to do so. He tied Norman with a bandage and his legs and hands were cuffed. They forced him to lie down and he was covered with a blanket and rolled with it so that he could face up. One of the Applicant's colleagues sat on his legs. The Applicant administered the notorious "tube torture" method to suffocate him. This was done for five to six times as the Applicant would put the tube on and off his face to exert pressure."