The US Government has launched a criminal investigation into controversial CIA interrogations carried out as part of the so-called "war on terror". Newly declassified documents reveal allegations that interrogators threatened to kill the children of one suspect and threatened another with an electric drill. Interrogators also allegedly threatened to sexually assault a prisoner's mother in front of his eyes unless he spoke and repeatedly pinched the carotid artery of another man, causing him to nearly pass out. The Bush administration has already come in for widespread criticism for allowing the CIA to use "enhanced interrogation techniques" that many say were tantamount to torture.