The alleged evidence against the Saudis on 9-11

Telegraph:

Evidence of a possible link between the Saudi government and the September 11 attacks has emerged just as President Barack Obama arrives in Saudi Arabia for a visit intended to smooth relations.

Speculation has swirled for years as to whether high-ranking Saudi officials had prior knowledge of the terrorist attacks in New York and Washington.

Now it has been revealed that a document tying an al-Qaeda bomb maker to the planning of the attacks was discovered inside an envelope from the Saudi Embassy in Washington.

Ghassan al-Sharbi, the bomb maker, took flying lessons alongside some of the 9/11 hijackers, though he did not participate directly in the attacks.

He was arrested in 2002, and documents that he had hidden were subsequently discovered. Among them was his flight school certificate, which was found tucked inside the government envelope.

Al-Sharbi is currently held in the Guantanamo Bay detention facility in Cuba.

Brian McGlinchey, a blogger who has advocated for the US government to declassify documents relating to 9/11, found a reference to the envelope in a US government document on FBI counter-terrorism investigations.

The document identifies al-Sharbi as a Saudi student who took flight lessons near Phoenix, Arizona before being captured in the same location as Abu Zubaida, a suspected al-Qaeda fighter also currently held at Guantanamo Bay.

"After al-Sharbi was captured, the FBI discovered that he had buried a cache of documents nearby, including an envelope from the Saudi Embassy in Washington that contained al-Sharbi's flight certificate," the document reads.
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This is an interesting tidbit tying the Saudis to a guy who was apparently part of the plot  and still resides at Gitmo.  Have the Saudis ever been asked to explain how the envelope came into the possession of the bomb maker?