Five years after the Sept. 11, 2001, terror attacks, 60 percent of the knowledge of the U.S. intelligence community about Al Qaeda, its leadership structure and its operations came from enhanced interrogation techniques. 

That's what former CIA Director Michael Hayden told FOX News late last year. 

Other U.S. officials told FOX News on Tuesday that they stand by a May 2005 memo that said that enhanced techniques used in interrogations "have led to specific, actionable intelligence as well as a general increase in the amount of intelligence regarding Al Qaeda and its affiliates."

On Tuesday, President Obama's national intelligence director argued in a memo to staff -- and a public statement -- that it's impossible to know whether CIA interrogators would have gleaned the same information using techniques that are not deemed controversial. 

DNI Dennis Blair added that waterboarding and other approved methods that have now been abandoned damaged the United States' image abroad. 

"The information gained from these techniques was valuable in some instances, but there is no way of knowing whether the same information could have been obtained through other means. The bottom line is these techniques have hurt our image around the world, the damage they have done to our interests far outweighed whatever benefit they gave us and they are not essential to our national security," he said.

But U.S. officials familiar with the intelligence gained from the interrogations pointed to examples of how the chain of information expanded. They detailed how in the spring of 2002, Abu Zubaydah, Al Qaeda's operations chief who ran the training camps in Afghanistan where the Sept. 11 hijackers were trained, was picked up in Pakistan

Zubaydah was nearly killed in the fire fight and was saved by U.S. Army doctors. 

He ended up providing leads to Ramzi bin al-Shibh, who was also captured in Pakistan. Bin al-Shibh was part of the Hamburg, Germany, cell of Al Qaeda where Sept. 11 hijacker Mohammed Atta was also stationed. 

The information from Zubaydah and from bin al-Shibh led to the capture in the spring of 2003 of Khalid Sheik Mohammed, the architect of the Sept. 11 attacks, according to U.S. officials.

A close reading of the memo from May 2005 shows that U.S. officials learned during the Mohammed interrogations about a "Second Wave" of attacks aimed for Los Angeles. 

It also led to the unraveling of a cell in Southeast Asia led by Riduan bin Isomuddin, better known as Hambali, who was head of an Al Qaeda-affiliated group that was identified with the Bali nightclub bombing in 2002 that was responsible for the deaths of more than 100 people. 

The capture of Hambali enabled confirmation of other information provided by Mohammad, according to the officials. 

Zubaydah also provided significant information on two operatives, including Jose Padilla, who planned to detonate a dirty bomb in the Washington, D.C., area, the officials noted.