The Sept. 11 commission examined the Saudi flights in its final report last year, and it found that no Saudis had been allowed to leave before national airspace was reopened on Sept. 13, 2001; that there was no evidence of "political intervention" by the White House; and that the F.B.I. had done a "satisfactory screening" of the departing Saudis to ensure they did not have information relevant to the attacks.

The documents obtained by Judicial Watch, with major passages heavily deleted, do not appear to contradict directly any of those central findings, but they raise some new questions about the episode.

The F.B.I. records show, for instance, that prominent Saudi citizens left the United States on several flights that had not been previously disclosed in public accounts, including a chartered flight from Providence, R.I., on Sept. 14, 2001, that included at least one member of the Saudi royal family, and three flights from Las Vegas between Sept. 19 and Sept. 24, also carrying members of the Saudi royal family. The government began reopening airspace on Sept. 13, but many flights remained grounded for days afterward.

The three Las Vegas flights, with a total of more than 100 passengers, ferried members of the Saudi royal family and staff members who had been staying at Caesar's Palace and the Four Seasons hotels. The group had tried unsuccessfully to charter flights back to Saudi Arabia between Sept. 13 and Sept. 17 because they said they feared for their safety as a result of the Sept. 11 attacks, the F.B.I. documents say.

Once the group managed to arrange chartered flights out of the country, an unidentified prince in the Las Vegas group "thanked the F.B.I. for their assistance," according to one internal report. The F.B.I. had interviewed many members of the group and searched their planes before allowing them to leave, but it nonetheless went back to the Las Vegas hotels with subpoenas five days after the initial flight had departed to collect further information on the Saudi royal guests, the documents show.

In several other cases, Saudi travelers were not interviewed before departing the country, and F.B.I. officials sought to determine how what seemed to be lapses had occurred, the documents show.

The F.B.I. documents left open the possibility that some departing Saudis had information relevant to the Sept. 11 investigation.