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.

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