Friends and allies

The episode could have been a chapter from the thriller written by former Senator Bob Graham of Florida about a shadowy Saudi role in the Sept. 11 attacks.

A top F.B.I. official unexpectedly arranges a meeting at Dulles International Airport outside Washington with Mr. Graham, the former chairman of the Senate Intelligence Committee, after he has pressed for information on a bureau terrorism inquiry. Mr. Graham, a Democrat, is then hustled off to a clandestine location, where he hopes for a breakthrough in his long pursuit of ties between leading Saudis and the Sept. 11 hijackers.

This real-life encounter happened in 2011, Mr. Graham said, and it took a startling twist.

"He basically said, 'Get a life,' " Mr. Graham said of the F.B.I. official, who suggested that the former senator was chasing a dead-end investigation.

Mr. Graham, 78, a two-term governor of Florida and three-term senator who left Capitol Hill in 2005, says he will not relent in his efforts to force the government to make public a secret section of a congressional review he helped write - one that, by many accounts, implicates Saudi citizens in helping the hijackers.

"No. 1, I think the American people deserve to know the truth of what has happened in their name," said Mr. Graham, who was a co-chairman of the 2002 joint congressional inquiry into the terrorist attacks. "No. 2 is justice for these family members who have suffered such loss and thus far have been frustrated largely by the U.S. government in their efforts to get some compensation."

He also says national security implications are at stake, suggesting that since Saudi officials were not held accountable for Sept. 11 they have not been restrained in backing a spread of Islamic extremism that threatens United States interests. Saudi leaders have long denied any connection to Sept. 11.

Mr. Graham's focus on a possible Saudi connection has received renewed attention because of claims made by victims' families in a federal court in New York that Saudi Arabia was responsible for aiding the Sept. 11 hijackers and because of a Freedom of Information Act lawsuit filed against the F.B.I. in Florida.

In sworn statements in the two cases, Mr. Graham has said there was evidence of support from the Saudi government for the terrorists. He also says the F.B.I. withheld from his inquiry, as well as a subsequent one, the fact that the bureau had investigated a Saudi family in Sarasota, Fla., and had found multiple contacts between it and the hijackers training nearby until the family fled just before the attacks.

Despite the F.B.I.'s insistence to the contrary, Mr. Graham said there was no evidence that the bureau had ever disclosed that line of investigation to his panel or the national commission that reviewed the attacks and delivered a report in 2004.

"One thing that irritates me is that the F.B.I. has gone beyond just covering up, trying to avoid disclosure, into what I call aggressive deception," Mr. Graham said during an interview in a family office in this Miami suburb, which rose on what was a dairy farm operated by Mr. Graham's father, also a political leader in Florida.