The F.B.I. gave personal airport escorts to two prominent Saudi families who fled the United States, and several other Saudis were allowed to leave the country without first being interviewed, the documents show.

The Saudi families, in Los Angeles and Orlando, requested the F.B.I. escorts because they said they were concerned for their safety in the wake of the attacks, and the F.B.I. - which was then beginning the biggest criminal investigation in its history - arranged to have agents escort them to their local airports, the documents show.

But F.B.I. officials reacted angrily, both internally and publicly, to the suggestion that any Saudis had received preferential treatment in leaving the country.

"I say baloney to any inference we red-carpeted any of this entourage," an F.B.I. official said in a 2003 internal note. Another F.B.I. official, speaking on condition of anonymity, said this week regarding the airport escorts that "we'd do that for anybody if they felt they were threatened - we wouldn't characterize that as special treatment."

The documents were obtained through a Freedom of Information Act lawsuit against the Justice Department by Judicial Watch, a conservative legal group, which provided copies to The New York Times.

The material sheds new light on the aftermath of the Sept. 11 attacks, and it provides details about the F.B.I.'s interaction with at least 160 Saudis who were living in or visiting the United States and were allowed to leave the country. Some of the departing Saudis were related to Osama bin Laden.

The Saudis' chartered flights, arranged in the days after the attacks when many flights in the United States were still grounded, have proved frequent fodder for critics of the Bush administration who accuse it of coddling the Saudis. The debate was heightened by the filmmaker Michael Moore, who scrutinized the issue in "Fahrenheit 9/11," but White House officials have adamantly denied any special treatment for the Saudis, calling such charges irresponsible and politically motivated.

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.

"Although the F.B.I. took all possible steps to prevent any individuals who were involved in or had knowledge of the 9/11/2001 attacks from leaving the U.S. before they could be interviewed," a 2003 memo said, "it is not possible to state conclusively that no such individuals left the U.S. without F.B.I. knowledge."

The documents also show that F.B.I. officials were clearly riled by public speculation stirred by news media accounts of the Saudi flights. They were particularly bothered by a lengthy article in the October 2003 issue of Vanity Fair, which included charges that the bureau considered unfair and led to an internal F.B.I. investigation that the agency named "Vanitybom." Internal F.B.I. correspondence during the review was addressed to "fellow Vanitybom victims."

Critics said the newly released documents left them with more questions than answers.

"From these documents, these look like they were courtesy chats, without the time that would have been needed for thorough debriefings," said Christopher J. Farrell, who is director of investigations for Judicial Watch and a former counterintelligence interrogator for the Army. "It seems as if the F.B.I. was more interested in achieving diplomatic success than investigative success."

Senator Charles E. Schumer, Democrat of New York, called for further investigation.

"This lends credence to the theory that the administration was not coming fully clean about their involvement with the Saudis," he said, "and we still haven't gotten to the bottom of this whole affair."

Copyright 2005 The New York Times Company