The White House statement gave no further details about the material, but an official briefed on the F.B.I. review said the bureau contacted 10 people and interviewed nine of them. It was not clear why the 10th person was not interviewed. The White House concluded that the interviews did not corroborate sexual misconduct accusations against Judge Kavanaugh, and could help his case, said the person briefed on the findings, who requested anonymity to discuss them.

But it is the judgments of senators that will determine Judge Kavanaugh’s fate.

Senators will be permitted to review the materials, in what the F.B.I. calls 302 interview summaries, in a secured room at the Capitol starting Thursday morning, or they can be briefed by a handful of staff members who are cleared to examine the material. After a day of review, the Senate is on track to take an initial vote on Judge Kavanaugh’s confirmation on Friday and possibly a final vote as early as Saturday.

Even before the material was sent to the Senate, Democrats complained that the F.B.I. investigation had been too narrow and failed to look extensively enough at the allegations lodged against Judge Kavanaugh, 53, a 12-year veteran of the federal appeals court in Washington.

Christine Blasey Ford, 51, a university professor in California, has accused him of sexually assaulting her when they were teenagers at a small party in high school, while Deborah Ramirez, 53, who works for a county housing department in Boulder, Colo., has alleged that he exposed his genitals to her during a party in college.

The F.B.I. initially interviewed four people identified by the Republican leadership of the Senate Judiciary Committee: Ms. Ramirez and three people whom Dr. Blasey recalled being in the house at the time of the party: Mark Judge, P.J. Smyth and Leland Keyser. All three have said they did not remember the party or witness misbehavior by Judge Kavanaugh, although Ms. Keyser told The Washington Post that she believes Dr. Blasey.