Former Attorney General Alberto Gonzales has implicated himself - yet again - in the Bush administration's torture program.

Gonzales told Talking Points Memo that he knew "enhanced interrogation techniques" were used against suspected terrorists.

"I was aware of the techniques. I did have knowledge," Gonzales explained in the exclusive interview. "[I] know that a number of lawyers worked to look to see whether it could be administered in a way that was consistent with the anti-torture statute and guidance was given by the Department of Justice while I was in the White House about how these techniques could be implemented to gather important information, in a dangerous period for our nation, to gather information from the enemy that would be in America's favor."

Records show that Gonzales played a key role in the Bush torture program, with the former US attorney general authoring the original torture memo.

The memo referred to Article III of the Geneva Convention as outdated when applied to Al-Qaeda and Taliban captured abroad and imprisoned in US bases across the world.

But months prior to the release of Gonzales' original memo, he had approved of the CIA's "borderline torture" of Abu Zubaydah, according to a National Public Radio report in 2009. This approval was unusual in that the White House usually never advises agencies outside itself and called into question the CIA's policy review process that spring.

Colonel Lawrence Wilkerson, once chief of staff to Bush's first secretary of state, Colin Powell, has said that he learned from Powell that President Bush had the inside scoop on counter-terrorism policy involving torture techniques.

"I learnt that it was his view that it was not just vice president [Dick] Cheney and secretary [Donald] Rumsfeld, but also president Bush who was involved in all of the Guantanamo decision-making," The Times in London reported Wilkerson as saying.

Moreover, Wilkerson alleged Bush's vice president, Dick Cheney, and defence secretary Donald Rumsfeld knew that most detainees held at the US detention camp in 2002 were innocent but believed it was "politically impossible to release them."

President Barack Obama, who pledged to shut the prison, has not yet done so.

Wilkerson's statement was filed in support of the lawsuit of Adel Hassan Hamad, a Sudanese man held at Guantanamo Bay from March 2003 until December 2007. Hamad claimed he was tortured by US agents and filed a damages action, The Times said.

But Gonzales, currently a professor at Texas Tech, wouldn't say whether President George W. Bush ordered the torture of the man accused of planning Sept. 11, in spite of the fact that Bush's new book noted that the president "Damn right" ordered the CIA to waterboard Khalid Sheikh Mohammed.

"Yeah, I'm not going to comment on that, I'm going to save that for the book," Gonzales told TPM.

A growing number of lawmakers are calling for an investigation following Bush's open admission that he approved waterboarding and would do so again.

"It is absolutely vital that a thorough review of President Bush’s now admitted ordering of waterboarding take place," said Rep. John Conyers (D-MI).

With AFP and earlier reporting by Jeremy Gantz.