April 14, 2015 "ICH" - "NYT" - MIAMI LAKES, Fla. — 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.

The F.B.I. dismisses such criticism. In a new review of the bureau in the aftermath of Sept. 11, a three-person commission issued a blanket declaration that the family in Sarasota had nothing to do with the hijackers or their attacks. The review placed blame for an initial F.B.I. report of “many connections” between the family and terrorists on a special agent who, under bureau questioning, “was unable to provide any basis for the contents of the document or explain why he wrote it as he did.”

Still, a federal judge in South Florida is reviewing an estimated 80,000 documents related to the F.B.I.’s inquiry in Florida to determine what to release. Mr. Graham suggested that those documents could include photographs and records of cars linked to the hijackers entering the gated community where the Sarasota family lived.

“That will be a real smoking gun,” Mr. Graham said.

The case received unexpected attention this year when a former operative for Al Qaeda described prominent members of Saudi Arabia’s royal family as major donors to the terrorist network in the late 1990s. The letter from t he Qaeda member, Zacarias Moussaoui, prompted a statement from the Saudi Embassy saying the national Sept. 11 commission rejected allegations that Saudi officials had funded Al Qaeda.

Mr. Graham’s stature has added weight both to the push for disclosure of the classified 28 pages of the congressional inquiry as well as the legal fight to make public F.B.I. documents about the investigation of the Saudi family in Sarasota.

“He has been behind us all the way in terms of bringing attention to this,” said Dan Christensen, editor and founder of the Florida Bulldog, the online investigative journal that filed the Freedom of Information Act lawsuit against the F.B.I and the Justice Department.

Mr. Graham’s refusal to drop what many in the intelligence community consider to be long-settled issues has stirred some private criticism that the former senator has been out of the game too long and is chasing imagined conspiracies in an effort to stay relevant as he lectures and writes books. Intelligence officials say the claims in the secret 28 pages were explored and found to be unsubstantiated in a later review by the national commission.

Former colleagues are not so ready to write off a lawmaker they remember for sounding the alarm against the invasion of Iraq. He warned that shifting attention to removing Saddam Hussein would debilitate efforts to rid Afghanistan of Al Qaeda, which Mr. Graham said posed a far greater threat to the United States.

“Bob Graham has proven to be prescient about many things,” said Jane Harman, the former California congresswoman who once served as the top Democrat on the House Intelligence Committee.

Never one of the flashiest members of the Senate, Mr. Graham was seen more as a cautious, conscientious lawmaker eager to dig into the dry details of policy. His unglamorous reputation no doubt contributed to his inability to catch on during an abbreviated run for the Democratic presidential nomination in 2003. But his colleagues also saw him as a man who would not be easily dissuaded.

“Bob is kind of quiet, but once he is on to something, he is like a dog with a bone,” said Tom Daschle, the former Senate Democratic leader.

Noting that his wife, Adele, accuses him of “failing at retirement,” Mr. Graham remains involved in Florida conservation issues and other state causes. He has also written books, including the Sept. 11 suspense novel “Keys to the Kingdom,” and handed down his interest in politics and public service to his four daughters, one of whom, Gwen, was elected to the House from North Florida last year.

Mr. Graham said he simply wanted to make certain any co-conspirators in the Sept. 11 attacks were made to pay.

“To me, the most simple, unanswered question of 9/11 is, did the 19 hijackers act alone or were they assisted by someone in the United States?” he said. “The official position of the United States government is they acted alone.”

“My motivation is to try to answer that question,” he said. “Did they act alone or did they have a support structure that made 9/11 possible?”