Now, in sworn statements that seem likely to reignite the debate, two former senators who were privy to top secret information on the Saudis’ activities say they believe that the Saudi government might have played a direct role in the terrorist attacks.

“I am convinced that there was a direct line between at least some of the terrorists who carried out the September 11th attacks and the government of Saudi Arabia,” former Senator Bob Graham, Democrat of Florida, said in an affidavit filed as part of a lawsuit brought against the Saudi government and dozens of institutions in the country by families of Sept. 11 victims and others. Mr. Graham led a joint 2002 Congressional inquiry into the attacks.