WASHINGTON, April 3: The key evidence against the only person convicted in the US for his connection to the 9/11 attacks came largely from a senior Al Qaeda leader arrested in Pakistan, US and diplomatic sources told Dawn.

The Bush administration is seeking death sentence for Zacarias Moussaoui, a 37-year- old Frenchman of Moroccan descent, for his alleged role in the Sept 11, 2001 attacks.

A key piece of evidence in the sentencing trial of Moussaoui is a 58-page deposition from Khaled, who was captured in Pakistan in 2003, interrogated by Pakistani and US intelligence officers and later brought to the US prison camp at Guantanamo Bay, Cuba.

So far almost all senior Al Qaeda operatives in US custody have either been arrested in Pakistan or have been held with Pakistan’s assistance.

Diplomatic sources in Washington say that this explains Pakistan’s importance in the war on terror. Aware of this importance, the sources say, the US administration continues to seek close ties with Pakistan despite a strong opposition from the American media and the academia.

In the case against Moussaoui, the initial information came from US sources as he was arrested in the US before 9/11. But this was not enough to sentence Moussaoui and the prosecutors needed some additional information to link him to Al Qaeda. This came from Khaled’s deposition.

Besides offering insight into Moussaoui’s place in the Al Qaeda hierarchy, the document is perhaps also the most detailed depiction of how the Sept 11 conspiracy unfolded.

In his deposition, Khaled Sheikh Mohammed claims he had been trying to persuade Al Qaeda to attempt a dramatic hijacking operation since the early 1990s. Osama bin Laden always rejected him, saying the idea was impractical — until the spring of 1999, when he met Osama in Kandahar and convinced him to endorse his plan.

At first, Khaled planned a two-pronged attack. One prong would consist of aircraft used as missiles to attack targets on America’s East Coast. The second would be the simultaneous explosion of other hijacked aircraft in East Asia.

Eventually, the project was simplified in the name of efficiency and the attacks were confined to the US mainland.

In the end, the plot involved 34 participants, broken down into six groups that were based on degree of knowledge of operational details.

The top group included Osama, Khaled, and other top officials, as well as a little-known, mysterious figure, Abu Turab al-Urduni who allegedly trained the hijackers in Afghanistan prior to their deployment.

Obtaining US visas was a continuing problem. But, according to the deposition, Al Qaeda managed to get 15 hijackers who either had US visas or could get them. Four hijackers each were for three planes used in the first wave of attacks while three for the fourth plane, which was to go for the White House later.