Brett Kavanaugh has denied allegations he attempted to force himself on a fellow high school student more than 30 years ago.

“I categorically and unequivocally deny this allegation. I did not do this back in high school or at any time,” the US Supreme Court nominee said, responding to a report detailing allegations from a woman who reportedly attended a high school near his in the 1980s.

The woman reportedly sent a letter describing her allegations to senator Dianne Feinstein, the ranking minority member of the Senate Judiciary Committee, weeks before the judge’s Senate confirmation hearing began. According to the New Yorker, the woman felt moved to take action after Donald Trump nominated Mr Kavanaugh to the Supreme Court in July.

Ms Feinstein initially kept the letter private, but revealed its contents to the other Democrats on the committee on Wednesday, amid mounting questions from reporters and other members of Congress.

On Thursday, the senator released a statement saying she had received information on Mr Kavanaugh from a source who requested to remain anonymous, and had referred the matter to federal authorities.

Supreme Court nominee Brett Kavanaugh delivers opening statement

Republicans in Congress quickly leapt to Mr Kavanaugh's defence.

“Let me get this straight: this is [a] statement about [a] secret letter regarding a secret matter and an unidentified person. Right,” senator John Cornyn‏ tweeted in response to Ms Feinstein’s statement.

On Friday – the same day the New Yorker published its report – judiciary committee chairman Chuck Grassley released a letter from 65 women who knew Mr Kavanaugh in high school. The women wrote that he had “behaved honourably and treated women with respect” during that time.

“Through the more than 35 years we have known him, Brett has stood out for his friendship, character, and integrity,” the women wrote. “In particular, he has always treated women with decency and respect. That was true when he was in high school, and it has remained true to this day.”

Women's March 2018 across the world: in pictures Show all 35 1 /35 Women's March 2018 across the world: in pictures Women's March 2018 across the world: in pictures London Women's rights demonstrators hold placards and shout slogans during the Time's Up rally at Richmond Terrace, opposite Downing Street in London. Getty Women's March 2018 across the world: in pictures London The Time's Up initiative was launched at the start of January 2018 as a response to the #MeToo movement and the Harvey Weinstein scandal. AFP/Getty Women's March 2018 across the world: in pictures Berlin Women's March in Berlin. EPA Women's March 2018 across the world: in pictures London The Time's Up Women's March marks the one year anniversary of the first Women's March in London and in 2018 it is inspired by the Time's Up movement against sexual abuse. Getty Women's March 2018 across the world: in pictures Paris Women hold a banner reading "still feminist" with the Eiffel tower in background on the Trocadero esplanade in Paris. AFP/Getty Women's March 2018 across the world: in pictures London Protesters hold up placards at the Women's March in central London. Rex Women's March 2018 across the world: in pictures Paris A demonstator hold signs on the Trocadero esplanade in Paris during a women's march organised as part of global protests. AFP/Getty Women's March 2018 across the world: in pictures London Chanting Times Up in the cold rain - On the anniversary of the Women's March on London. Rex Women's March 2018 across the world: in pictures New York Thousands of people gather holding protest signs on Central Park West. EPA Women's March 2018 across the world: in pictures New York Demonstrators take part in the Women's March in Manhattan Reuters Women's March 2018 across the world: in pictures Chicago A woman holds a sign during the Second Annual Womens March in Chicago AFP/Getty Women's March 2018 across the world: in pictures New York People gather near Central Park before the beginning of the Women's March in New York Getty Women's March 2018 across the world: in pictures Washington Supporters gather during the Women's March in Washington AFP/Getty Women's March 2018 across the world: in pictures New York The crowd lines up near Central Park Getty Women's March 2018 across the world: in pictures Chicago Demostrators attend the Second Annual Womens March in Chicago AFP/Getty Women's March 2018 across the world: in pictures New York Thousands hold signs and rally while attending the Women’s March in New York Getty Women's March 2018 across the world: in pictures New York People gather near Central Park before the beginning of the Women's March in New York Getty Women's March 2018 across the world: in pictures Washington People participate in the second annual Women's March in Washington Reuters Women's March 2018 across the world: in pictures New York People hold signs up during the women's march Getty Women's March 2018 across the world: in pictures Philadelphia Oscar Janicki, 6, participates in the Second Annual Women's March in Philadelphia Reuters Women's March 2018 across the world: in pictures Philadelphia Crowds gather to participate in the Second Annual Women's March in Philadelphia Reuters Women's March 2018 across the world: in pictures Washington People participate in the second annual Women's March in Washington Reuters Women's March 2018 across the world: in pictures New York Women pose as they attend the second annual National Womens March in New York City AFP/Getty Women's March 2018 across the world: in pictures Washington People participate in the second annual Women's March in Washington Reuters Women's March 2018 across the world: in pictures New York People gather prior to the second annual National Womens March in New York City AFP/Getty Women's March 2018 across the world: in pictures New York People take part in the Women's March in Manhattan Reuters Women's March 2018 across the world: in pictures New York People gather the second annual National Womens March AFP/Getty Women's March 2018 across the world: in pictures Washington People participate in the Second Annual Women's March in Washington Reuters Women's March 2018 across the world: in pictures Rome A woman holds a banner reading "Womwn united will never be defeated" during Rome Resists demonstration part of the Women's March in downtown. AFP/Getty Women's March 2018 across the world: in pictures Rome Italian actress Asia Argento (3rdL) attends the Rome Resists demonstration part of the Women's March in downtown Rome. AFP/Getty Women's March 2018 across the world: in pictures Rome The Women's March Rome, designed to show solidarity for the protection of civil and social rights, women's rights and the environment included Italian actress Asia Argento, one of the first women to accuse US film producer Harvey Weinstein of sexual assault. AFP/Getty Women's March 2018 across the world: in pictures Zurich A US citizen holds a poster on the anniversary of the inauguration of President Trump apologising to the world on behalf of her country, in Zurich, Switzerland. A year after millions of people took to the streets across the US and countries around the world, women's marches are being held in lots of cities this weekend. EPA Women's March 2018 across the world: in pictures New York People take part in the Women's March in Manhattan Reuters Women's March 2018 across the world: in pictures Rome A woman holds a banner reading "The rising of the women means rising of us all" during Rome Resists demonstration. AFP/Getty Images Women's March 2018 across the world: in pictures Rome A woman lifts her fist while holding a banner reading "Hear our voice" during Rome Resists demonstration. AFP/Getty

But the news also sparked outcry from a number of women's rights groups, including Planned Parenthood, NARAL Pro-choice America, and UltraViolet, who urged the judge to withdraw his nomination.

“A woman’s identity should not have to be revealed to take her story seriously and pursue justice on her behalf," NARAL President Ilyse Hogue said in a statement.