© NABush admits approving waterboarding of CIA detainees.

Former US president George Bush has admitted that he personally approved a request by CIA agents to use waterboarding -- a form of torture that simulates drowning.

In his book "Decision Points," to hit the shelves on Tuesday, Bush makes it clear that he approved the use of waterbording in interrogation of so-called "terror suspects."

He recalls in the memoir that when the CIA asked him whether it could proceed with waterboarding of Khalid Sheik Mohammed, the alleged plotter of the 9/11 attacks, he replied "Damn right," The Washington Post reported.

He seeks to justify his decision, claiming Muhammed was suspected of knowing about future terrorist plots against the US.

The 43rd president of the United States said he would make the same decision again if he believed it would save lives.

Former Vice President Dick Cheney has also acknowledged supporting torture.

"I was a big supporter of waterboarding," he said in a television interview in February.

While President Barack Obama has agreed that waterboarding is an act of torture which is illegal according to the international law, and the Geneva Convention, he has stopped short of bringing former officials to justice for sanctioning it.

Some human rights experts say the admission could have legal consequences for Bush and expose him to prosecution.

Others, however, believe that the prosecution is unlikely.

"The fact that he did admit it suggests he believes he is politically immune from being held accountable. . . . But politics can change," says David Cole, a Georgetown University law professor.