Tara Reade, a former Senate employee who alleged Joe Biden sexually assaulted her 27 years ago, is being represented by a prominent lawyer and political donor to President Donald Trump’s 2016 Republican campaign.
Douglas Wigdor told The Associated Press he was not currently being paid for his work with Ms Reade.
His firm also denied there was a political motivation for his decision to represent Ms Reade in her accusations against Mr Trump’s presumptive Democratic opponent in the November US election.
“We have decided to take this matter on because every survivor has the right to competent counsel,” the firm said in a statement.
Ms Reade has said for weeks that she was struggling to find a lawyer willing to represent her.
She has accused Mr Biden of sexually assaulting her in 1993, when she worked on his Senate staff. He has denied her allegation.
On Thursday, Ms Reade said she wanted Mr Biden to be “held accountable” and called on him to drop out of the presidential race.
Her comments came in her first on-camera interview, conducted by former Fox News and NBC News journalist Megyn Kelly.
Pressed by a Florida television station about Ms Reade’s comment, Mr Biden reiterated his denial of the allegation.
“The truth is what matters,” he told Bay News 9. “In this case, the truth is these claims are flat-out false.”
Mr Wigdor is well known for his work on prominent cases related to sexual harassment and assault.
He represented six women who accused Harvey Weinstein, the disgraced Hollywood producer, of sexual misconduct.
In 2018, he spoke out in the media defending Christine Blasey Ford, the woman who accused Supreme Court nominee Brett Kavanaugh of sexual assault.
Mr Wigdor has been a supporter of Mr Trump and provided about 55,000 dollars (£44,000) in campaign contributions in 2016, according to Federal Election Commission records.
He has not donated to either Mr Trump’s or Mr Biden’s 2020 campaign.
Mr Wigdor said he plans to help Ms Reade in her dealings with the media and any independent investigations into her allegations that might occur.
He said the two have not discussed bringing a lawsuit based on her claims, but he did not rule that out.
Mr Wigdor suggested Ms Reade’s earlier struggles to find a lawyer to represent her were the result of “politics”.
“I think highly of a lot of these people,” he said. “These are my friends and colleagues, people who I respect, but they tend to be Democrats or liberals, and they were not interested, because of that, in representing Tara Reade.”
Ms Reade first spoke out about her alleged interactions with Mr Biden in 2019, telling journalists he had touched her inappropriately while she worked on his Senate staff.
She came forward in 2020, around the time Mr Biden became the presumptive Democratic nominee, with new allegations of assault.
She says she did not initially disclose the assault allegations because she was scared of backlash and was still coming to terms with what had happened to her.