A letter about Supreme Court nominee Brett Kavanaugh that a top Senate Democrat referred to law enforcement details an accusation of sexual misconduct against the judge, The New Yorker reported Friday.

Kavanaugh denies the allegation.

A woman who did not want to be identified accuses the judge of trying to force himself on her during a party when they were both in his school in the early 1980s, according to the magazine. The New Yorker report says the woman claims Kavanaugh and a friend increased the volume of music to conceal an outcry from her, and that the judge covered her mouth before she got away.

Kavanaugh said in a statement, conveyed by White House spokesman Raj Shah: "I categorically and unequivocally deny this allegation. I did not do this back in high school or at any time."

The sexual misconduct allegation surfaces as Republicans move through a bitter process of confirming Kavanaugh as a Supreme Court justice. It is unclear now how it will affect Kavanaugh's chances of serving on the highest U.S. court as senators decide whether to vote for him during a national reckoning over sexual misconduct.

Kavanaugh's confirmation hearing in the Senate Judiciary Committee will go on as scheduled on Thursday, said Taylor Foy, a spokesman for the panel's chairman, Republican Sen. Chuck Grassley of Iowa. Foy added that nothing resembling the misconduct allegation came up during previous FBI examinations of the judge's background.

The woman first detailed the allegation over the summer in a letter to her representative, Anna Eshoo of California, but decided not to speak publicly about it, The New Yorker said. Sen. Dianne Feinstein, a California Democrat and ranking member on the Senate Judiciary Committee, eventually received the letter, as well. The New Yorker did not detail how it knew about the contents of the letter.

Feinstein first declined to share details with the committee's other Democrats, before agreeing to fill them in on Wednesday, according to The New Yorker. On Thursday, she said she referred the information to federal authorities. The FBI reportedly does not plan to open an investigation into the claim, and the bureau included the letter as an update to Kavanaugh's background check given to the White House.

In a statement, a spokesman for Feinstein said the senator "took these allegations seriously and believed they should be public." The accuser "made it clear" that she did not want the information to be public.

"It is critical in matters of sexual misconduct to protect the identity of the victim when they wish to remain anonymous, and the senator did so in this case," the spokesman said.

Read the full New Yorker story here.