Responding to requests from House Republicans, the FBI sent members of Congress the notes from its July interview with Hillary Clinton about her private email server Tuesday.
"The FBI has turned over a number of documents related to their investigation of former Secretary Clinton's use of a personal email server," a House Oversight committee spokesperson told NBC News in a statement. "Committee staff is currently reviewing the information that is classified secret. There are no further details at this time."
The FBI confirmed that it is "providing certain relevant materials to appropriate congressional committees to assist them in their oversight responsibilities in this matter."
"The material contains classified and other sensitive information and is being provided with the expectation it will not be disseminated or disclosed without FBI concurrence," it said.
Deputy State Department "spokesman Mark Toner said at a news briefing Tuesday that the agency "obviously respects the FBI's desire to accommodate the request of its committees of oversight in Congress, just as we do with our oversight committees."
"We're going to continue to cooperate, just as we have with the FBI in every step of the process," he said.
But Adam Schiff of California, ranking Democrat on the House Intelligence Committee, called the decision a mistake.
"With the exception of the classified emails that had been found on the private server, I can see little legitimate purpose to which Congress will put these materials," Schiff said in a statement. "Instead, as the now-discredited Benghazi Committee demonstrated, their contents will simply be leaked for political purposes."
Clinton was interviewed by five or six agents July 2 at FBI headquarters in Washington. On the following Tuesday, FBI Director James Comey announced that the FBI would not recommend prosecuting her.
When members asked for a copy of the interview notes, Comey told a House committee on July 7: "We will provide you with whatever we can under the law and under our policy."
He also said the notes were classified top secret. An FBI official said Monday that since last month's hearing, FBI lawyers have been reviewing whether the notes can be turned over and whether any redactions were necessary.
The notes are not verbatim transcripts of the interview, which Comey said lasted 3½ hours. Under the FBI's longstanding policy, agents do not make audio or video recordings of their interviews. Instead, summaries are written on FBI Form 302, and have come to be known as 302s.
An FBI policy paper explains that "the presence of recording equipment may interfere with and undermine the successful rapport-building interviewing technique which the FBI practices."
Two years ago, however, the Justice Department said FBI agents should begin recording interviews, but only involving "individuals in federal custody, after they have been arrested but before their initial appearance" in court.
That rule did not apply to the Clinton interview, which was voluntary. She was not in custody, nor had she been arrested.
Separately, two House Republicans sent a letter Monday to the U.S. attorney in Washington, listing statements she made in congressional hearings about the e-mail issue while she was secretary of state.
Bob Goodlatte of Virginia, chairman of the Judiciary Committee, and Jason Chaffetz of Utah, chairman of the Oversight and Government Reform Committee, have urged the FBI to investigate whether the testimony amounted to perjury.
The Clinton campaign, meanwhile, criticized the Republicans' motives Tuesday.
"This is an extraordinarily rare step that was sought solely by Republicans for the purposes of further second-guessing the career professionals at the FBI," said Brian Fallon, a national spokesman for the Clinton campaign.
"We believe that if these materials are going to be shared outside the Justice Department, they should be released widely so that the public can see them for themselves, rather than allow Republicans to mischaracterize them through selective, partisan leaks," he said.