Roy Moore accused of groping woman when she was 16 and pushing her head down

Mr Moore's campaign says he is 'an innocent man and has never had any sexual misconduct with anyone'

Beverly Young Nelson speaks to the media at a news conference where she accused Alabama Republican Senate candidate Roy Moore of sexually abusing her (Getty)

Another woman has accused Roy Moore, a Senate candidate in Alabama, of sexually abusing her when she was a minor.

Beverly Young Nelson claims Mr Moore sexually assaulted her when she was 16. The Alabama resident, now 56, says Mr Moore was 39 years old and working as a district attorney when he allegedly forced himself on her in his car.

Ms Nelson told reporters on Monday that Mr Moore had been a regular at the restaurant where worked as a teenager. Through tears, she described a night in which he allegedly offered to drive her home.

Instead of taking her home, Ms Nelson claimed, the candidate drove into a dark area, locked the doors of his car, and began groping her breasts. When she fought and screamed, she alleged, he grabbed her neck and attempted to force her head toward his crotch.

The allegations make Ms Nelson the fifth woman to accuse Mr Moore of past sexual misconduct with a teenager.

Mr Moore – a populist favourite backed by former White House adviser Steve Bannon – denied the claims in a statement. He called Ms Nelson's lawyer, Gloria Allred, a "sensationalist leading a witch hunt".

"We’ve said this before and we’ll say it again: Judge Moore is an innocent man and has never had any sexual misconduct with anyone," the campaign said. "This is a witch hunt against a man who has had an impeccable career for over 30 years and has always been known as a man of high character."

In the press conference, Ms Nelson claimed the abuse started when she was just 15. Mr Moore would visit her at the restaurant, she said, and compliment her appearance and pull her hair. One day, she brought her high school yearbook to work. Mr Moore allegedly asked to sign it.

At the press conference, Ms Allred passed around photocopies of an old yearbook page. A note in the top right corner, dated Christmas 1977, read: “To a sweeter more beautiful girl I could not say 'Merry Christmas'."

It was signed: "Love, Roy Moore, DA.”

Ms Nelson claimed the alleged assault happened a week or two after the yearbook signing. After finishing her evening shift, she said, she waited outside the restaurant for her boyfriend to pick her up. When he did not show up, Mr Moore offered to drive her home.

"I trusted Mr. Moore. He was the district attorney. I thought that he was simply doing something nice by offering to drive me home," Ms Nelson said, her voice shaking. "I did not want to wait outside in the cold so I agreed."

Once she was in the car, Ms Nelson said, Mr Moore allegedly began groping her and forcing her head down, despite her protestations. When he finally opened the car door, she said he told her: “If you tell anyone about this, no one will ever believe you."

Ms Nelson said she had not come forward with her claims earlier because she was afraid of Mr Moore and the power he wielded as district attorney.

But she did eventually tell her mother and sister about the incident, Ms Nelson told reporters. Ms Allred said the women remember their family member becoming upset whenever she saw Mr Moore on the television.

Ms Nelson's claims come in the wake of a Washington Post report alleging Mr Moore initiated sexual contact with a 14-year-old girl when he was 32. Ms Nelson – who voted for Donald Trump in the presidential election – said she was inspired to come forward after reading the article.

“I want Mr Moore to know that he no longer has any power over me and I no longer live in fear of him," she said.

Roy Moore, seen here speaking at the Values Voter Summit of the Family Research Council in Washington, DC on October 13, 2017, faces allegations of pursuing relationships with underage women (REUTERS/James Lawler Duggan) (Reuters)

Mr Moore has denied the claims from the Post article, and even threatened to sue the publication. Despite a media uproar, and pushback from his party, he has vowed to stay in the Senate race.

On Monday morning, before the press conference, Senate Majority Leader Mitch McConnell urged the former judge to step down.

"I believe the women," Mr McConnell said. "I think he should step aside."

Other prominent Republicans joined in the chorus after the press conference.

Cory Gardner, the National Republican Senatorial Committee Chairman, said Mr Moore was “unfit to serve in the United States Senate and he should not run for office".

“If he refuses to withdraw and wins, the Senate should vote to expel him, because he does not meet the ethical and moral requirements of the United States Senate,” Mr Gardner added.

Senator John Cornyn of Texas also withdrew his endorsement after the press conference. More than a dozen Senate Republicans had already urged Mr Moore to step down in the wake of the Post allegations.

It is too late to remove Mr Moore's name from the ballot, but Senate leaders say they are looking at staging a write-in campaign. The election is scheduled for 12 December.