Women tweet photos of when they were 14 in response to sexual misconduct accusations against US politician Roy Moore. (Twitter)

Women tweet photos of when they were 14 in response to sexual misconduct accusations against US politician Roy Moore. (Twitter) Source: Twitter

Republican candidate Roy Moore has been accused of molesting a 14-year-old girl when he was in his 30s.

Women are sharing photos of themselves when they were 14 years old in protest against a Republican candidate for the United States Senate who has been accused of sexually abusing a 14-year-old girl.

Roy Moore, a 70-year-old former state judge and Christian evangelical, is accused of trying to engage in sexual encounters with four women aged 14 to 18 when he was in his 30s, according to a Washington Post investigation.

The Republican nominee in Alabama for a US Senate seat says he has "never engaged in sexual misconduct" and called the allegations a "dangerous lie" that would harm real victims of molestation.

Some Republicans are calling on Moore to step down as the party's nominee in the December 12 election, but others are defending him.

In response to those defending Moore, comedian and co-creator of "The Daily Show" Lizz Winstead started the hashtag #MeAt14 and posted a photo of herself, highlighting the fact that she was a child at age 14.

Celebrities, including actress Alyssa Milano and comedian Sarah Silverman, and many other women have posted their own photos and stories on social media, and by Sunday the hashtag was trending in the US.

Other women used the hashtag to reveal that at age 14 they had already been the victim of sexual abuse and harassment.

Some have criticised the hashtag for using photos of underage girls to protest the abuse of underage girls, while others have pointed out that using the term "dating a 32-year-old" is an inappropriate way to describe child abuse.

Women who are experiencing sexual or physical violence are encouraged to ring 1800-RESPECT, a national telephone support line.