A top Democratic vice presidential candidate defended Joe Biden against allegations he sexually assaulted an aide in the early 1990s, as more evidence supporting the claim emerged.

Stacey Abrams, a former Georgia gubernatorial candidate, told CNN's Don Lemon on Tuesday that women deserve to be heard and listened to, "but".

"I also believe that those allegations have to be investigated by credible sources," she said during the episode of CNN Tonight.

Ms Abrams is part of a growing number of Democrats either defending the ex-VP against the allegations or ignoring them, including Hillary Clinton and Elizabeth Warren who both endorsed Mr Biden this week with no reference to the incident.

Tara Reade recently filed an official police complaint against Mr Biden alleging he sexually assaulted her during the early 1990s.

Lemon, who said CNN had spoken to a former neighbour of Ms Reade about the incident, asked Ms Abrams if she was "applying a different standard" given tweets from 2018 about unproven allegations against Supreme Court Justice Brett Kavanaugh.

"I believe then and I believe now that women deserve to be heard because too often they are not, and Tara Reade deserved to have her story listened to and investigated," she said.

"The New York Times investigation does not support the accusations against the vice president. I believe the Biden I know and I think that he will make women proud, that he will make America proud."

The New York Times took 19 days to report the #MeToo allegation that Mr Biden put Ms Reade up against the wall and penetrated her with his fingers.

"I remember him saying, first, as he was doing it 'Do you want to go somewhere else?' and then him saying to me, when I pulled away... he said 'Come on man, I heard you liked me,'" Ms Reade alleged. "That phrase stayed with me."

Video surfaced recently of a 1993 Larry King Live episode that appeared to show the mother of Ms Reade referencing "problems" her daughter faced while working as a staffer for the then-US senator from Delaware.

Ms Reade confirmed on Twitter that the caller was her mother, who called in to the program in 1993 out of indignation of how she was treated when first trying to report the allegations.

Ms Abrams said that she didn't want women to be afraid to come forward, but that allegations should be investigated and borne out.

"I believe his [Mr Biden's] campaign has been very clear. And I believe that this is the approach that they intend to take and I support the approach."

A spokeswoman for Biden's campaign, Kate Bedingfield, has previously denied Reade's allegation, calling it "untrue."

"Such claims should also be diligently reviewed by an independent press. What is clear about this claim: it is untrue. This absolutely did not happen," she said.