WASHINGTON (AP) -- Sen. Dianne Feinstein, the top Democrat on the Senate Judiciary Committee, said she has notified federal investigators about information she received — and won't disclose publicly — concerning Supreme Court nominee Brett Kavanaugh.
The California Democrat said in a statement Thursday that she "received information from an individual concerning the nomination." She said the person "strongly requested confidentiality, declined to come forward or press the matter further, and I have honored that decision."
The FBI confirmed that it received the information Wednesday evening and included it in Kavanaugh's background file, which is maintained as part of his nomination. The agency said that is its standard process.
A Senate Democratic aide and another person familiar with the matter said it referred to an incident that occurred while Kavanaugh was high-school age. The two spoke to The Associated Press on condition of anonymity because they weren't authorized to discuss the matter.
The details of the alleged incident and the identity of the person who provided the information were unclear.
The White House called Feinstein's move an "11th hour attempt to delay his confirmation."
The Judiciary Committee, which has finished confirmation hearings for Kavanagh, is scheduled to vote next Thursday on whether to recommend that he be confirmed by the full Senate.
Feinstein's statement that she has "referred the matter to federal investigative authorities" jolted Capitol Hill and threatened to disrupt what has been a steady path toward confirmation for Kavanaugh by Republicans eager to see the conservative judge on the court.
Feinstein has held the letter close. Democratic senators on the panel met privately Wednesday evening and discussed the information, according to Senate aides who were not authorized to discuss the situation publicly and spoke on condition of anonymity.
Some senators, including the No. 2 Democrat, Dick Durbin of Illinois, learned about the information for the first time at the meeting, according to one of the aides.
A spokeswoman for Rep. Anna Eshoo, D-Calif., declined to confirm reports that the congresswoman had forwarded a letter containing the allegations to Feinstein. She said her office has a confidentiality policy regarding casework for constituents.
A White House spokeswoman, Kerri Kupec, said the FBI has vetted Kavanaugh "thoroughly and repeatedly" during his career in government and the judiciary.
She said Kavanaugh has had 65 meetings with senators — including with Feinstein — sat through over 30 hours of testimony and publicly addressed more than 2,000 questions. "Not until the eve of his confirmation has Sen. Feinstein or anyone raised the specter of new 'information' about him," she said.
Sen. John Cornyn of Texas, the second-ranking Republican and a member of the committee, was also skeptical.
"Let me get this straight: this is (sic) statement about secret letter regarding a secret matter and an unidentified person. Right," he tweeted.
Chairman Chuck Grassley, R-Iowa, was unaware of the information until it was made public, according to a GOP committee aide. Kavanaugh has undergone six federal background checks over time in government, including one most recently for the nomination, the aide said.
The new information on Kavanaugh was included Thursday in his confidential background file at the committee and is now available for senators to review, the aide said.
Democrats don't have the votes to block Kavanaugh's nomination if Republicans are unified, but they are fighting it and decrying the process that Republicans used to compile his government records for review.
At the committee Thursday, Republicans brushed aside a flurry of Democratic attempts to delay the consideration of Kavanaugh or subpoena more documents, sticking with a schedule that could see him confirmed by Oct. 1, when the new court session begins.
Feinstein had sought a subpoena for documents from Kavanaugh's time as President George W. Bush's staff secretary. She said senators "should be able to see this record" and wondered, "What in Judge Kavanaugh's records are Republicans hiding?"
The Republicans have declined to pursue Kavanaugh's staff secretary documents, saying it would be too cumbersome. They rejected Feinstein's motion and several others, including motions to subpoena documents and witnesses and a motion to adjourn.
Senate Judiciary Committee Chairman Chuck Grassley, R-Iowa, set the panel's vote on Kavanaugh for Sept. 20.
New documents released ahead of Thursday's meeting included Kavanaugh's 263-page written response to questions from senators, along with 28 files from the judge's work in the Bush White House that had been available to senators only on a "committee confidential basis." Democratic Sen. Cory Booker of New Jersey made the Bush documents public.
The documents released by Booker show Kavanaugh's involvement in Bush's nomination of Charles Pickering to an appellate court in the South as Pickering faced questions about his views on race relations. Kavanaugh had indicated in 2006 testimony that he was not substantially involved in the nomination.
In releasing a new batch of committee confidential documents about Kavanaugh, Booker was repeating a tactic that could prompt a review from the Senate Ethics Committee.
Booker's GOP colleagues and outside groups are criticizing him for releasing the documents. Last week, he released some documents that were later made public by the committee, but also others that weren't. Wednesday's disclosure brings the total to 75.
The conservative group Judicial Watch delivered a letter Wednesday to the Senate Ethics Committee seeking an investigation. It says Booker violated Senate rules against disclosing confidential documents and could face Senate expulsion.
Booker has welcomed the fight. He says the documents about Kavanaugh's work "raise more serious and concerning questions" about his honesty during his testimony before the committee.
At issue has been the unprecedented process the Senate Judiciary Committee used for gathering documents on Kavanaugh, an appellate court judge who is President Donald Trump's nominee to replace retired Justice Anthony Kennedy on the court.