After the terror attacks of Sept. 11, 2001, President Bush gave the CIA authority to conduct the now-controversial operations, called "renditions," and permitted the agency to act without case-by-case approval from the White House or other administration offices.
The highly classified practice involves grabbing terror suspects off the street of one country and flying them to their home country or another where they are wanted for a crime or questioning.
Some 100 to 150 people have been snatched up since 9/11. Government officials say the action is reserved for those considered by the CIA to be the most serious terror suspects.
Bush has said that these transfers to other countries — with assurances the terror suspects won't be tortured — are a way to protect the United States and its allies from attack. "That was the charge we have been given," he said in March.
But some operations are being questioned.
The CIA's inspector general, John Helgerson, is looking into fewer than 10 cases of potentially "erroneous renditions," according to a current intelligence official who spoke on condition of anonymity because the investigations are classified. Others in the agency believe it to be much fewer, the official added.
For instance, someone may be grabbed wrongly or, after further investigation, may not be as directly linked to terrorism as initially believed.
Human rights groups consider the practice of rendition a run-around to avoid the judicial processes that the United States has long championed. Experts with those groups and congressional committees familiar with intelligence programs say errors should be extremely rare because one vivid anecdote can do significant damage.
Said Tom Malinowski, Washington office director of Human Rights Watch: "I am glad the CIA is investigating the cases that they are aware of, but by definition you are not going to be aware of all such cases, when you have a process designed to avoid judicial safeguards."
He said there is no guarantee that Egypt, Uzbekistan or Syria will release people handed over to them if they turn out to be innocent, and he distrusts promises the U.S. receives that the individuals will not be tortured.
Bush and his aides have said the United States seeks those assurances — and follows up on them. "We do believe in protecting ourselves. We don't believe in torture," he said.
In the last 18 months, his administration has come under fire for its policies and regulations governing detentions and interrogations in the war on terror.