The Sept. 11 commission discounted a number of conspiracy theories that have been laid out in books, movies and magazine articles asserting that the FBI and the Bush administration committed improprieties in allowing bin Laden family members and other Saudis to jet back to their country in the days after the 2001 terrorist attacks.

In "Fahrenheit 9/11," filmmaker Michael Moore left the strong impression that the chartered bin Laden family flight, arranged by the Saudi Embassy in Washington because of concerns for their safety, occurred while civil aviation was grounded after the attacks. He also said the FBI did not properly interview the departing bin Ladens.

Author Craig Unger, in the book "House of Bush, House of Saud," also accused the FBI of only cursorily checking on bin Laden family members before letting them fly out of the country on Sept. 20. In addition, he said that even though civil aviation was allowed to resume on Sept. 13, 2001, federal authorities still limited the operation of private planes in this country, and he raised suspicions about the approval for the bin Laden flight.

In their report, released Thursday, the commissioners found nothing amiss in U.S. officials' decision to allow the nine chartered flights between Sept. 14 and 24 that carried 160 people, mostly Saudi nationals, to the desert kingdom. The report also concluded that FBI officials properly interviewed almost all the bin Laden family members, who were on one flight that departed Sept. 20, seven days after the grounding was lifted.

"We found no evidence that any flights of Saudi nationals . . . took place before the reopening of national airspace on the morning of September 13," the commission said. It added that it found "no evidence of political intervention" to allow the flights, noting that the highest-ranking official to sign off on them was then-White House counterterrorism chief Richard A. Clarke.

"We believe that the FBI conducted a satisfactory screening of Saudi nationals who left the United States on charter flights," the commission added. In details scattered over four pages of text and footnotes, the panel said the FBI interviewed "all persons of interest" on the flights, concluded that none was connected to the attacks and has "found no evidence to change that conclusion."

FBI officials kept close tabs on the Sept. 20 flight as it stopped in five U.S. cities to pick up bin Laden family members before leaving for Saudi Arabia. Twenty-two of the 26 people on board were interviewed by the FBI, and "many were asked detailed questions," the report said.

The bureau had more opportunity to get information from them than it ordinarily would have, the commission said, because the U.S. government does not routinely run checks on foreigners leaving the country. Collecting them in one location was fortunate for the FBI, because it could not have talked to them if they had simply left on regular commercial flights, it added.

Unger said he still thinks the FBI failed to adequately interview the bin Ladens and suspects that the Saudis received special treatment because authorities had grounded some private planes during that same period.

Joanne Doroshow, an associate producer of "Fahrenheit 9/11," said Moore did not intend to suggest that the bin Ladens flew away while civilian flights were grounded. She added that the filmmakers still harbor suspicions about the FBI interviews.

"We don't know who was interviewed and what questions were asked," she said.