Ghul was not waterboarded, or subject to near-drowning, the most notorious interrogation technique and one that critics describe as torture.
Two other CIA prisoners - al-Qaeda operations chief Khalid Sheikh Mohammed and his successor, Abu Faraj al-Libbi - gave their interrogators false information about the courier after they were waterboarded repeatedly, U.S. officials said.
Those lies also played a role in the decade-long manhunt, however. Over time, they were viewed as evidence by CIA analysts that bin Laden's top deputies were trying to shield a figure who might be a link to the al-Qaeda leader's hideout, according to U.S. officials briefed on the analysis. "The fact that they were covering it up suggested he was important," a U.S. official said.
In the end, intelligence gained from interviews with numerous detainees, high-tech eavesdropping and surveillance, and other investigative spadework provided insights into people who were close to bin Laden. No one source or bit of intelligence was so decisive or critical that it instantly solved the puzzle or ended the painstaking hunt for the world's most-wanted terrorist, officials said.
The nuances of that complex chain of events were often lost Wednesday amid a renewed public debate about the efficacy and morality of coercive interrogations that the CIA carried out under President George W. Bush.
"I think the issue has been mischaracterized on both sides," said a former CIA official involved in internal debate over the "enhanced interrogation techniques" program at the time. "The people who say 'enhanced interrogation techniques' directly led to catching bin Laden are wrong, and the people who say they had nothing to do with it are also wrong."
"There is no way that information obtained by EITs was the decisive intelligence that led us directly to bin Laden," said Tommy Vietor, spokesman for the National Security Council at the White House, using the acronym for enhanced interrogation techniques. "It took years of collection and analysis from many different sources to develop the case."
The Bush administration abandoned waterboarding by 2004 and closed the CIA's secret web of prisons. All the detainees were transferred to Guantanamo Bay by 2007.
The Obama administration has forsworn those interrogation tactics, and the CIA no longer captures or interrogates terror suspects, the agency says. The CIA has sharply increased armed Predator drones and military commando raids to kill terror suspects.
Things were much different in January 2004, when Kurdish military forces in Iraq picked up Ghul, an al-Qaeda courier who carried a letter sent by terrorist leader Abu Musab al-Zarqawi to bin Laden.
Ghul quickly disappeared into the CIA's network of secret prisons and was subjected to enhanced interrogation techniques, according to a Justice Department memo.
At first, his interrogators sought authorization to use "attention grasp, walling [slamming a detainee against a wall], facial hold . . . stress positions and sleep deprivation." But they concluded that Ghul had steeled himself to resist physical pressure, so they switched plans. The new measures included "dietary manipulation, nudity, water dousing and abdominal slap." The team believed "those techniques would be helpful because he appeared to have a particular weakness for food and also seemed especially modest."
A U.S. official noted that "just because something was approved doesn't mean all of them were used," but did not dispute force was used on Ghul.
"Ghul became relatively cooperative relatively quickly," the official said.