The woman, whose name has not been officially disclosed or published in the Swedish media but has been circulated widely on the Internet as one of the Assange accusers, wrote in a blogpost that she was "the victim of an assault" three years ago.
Friends of her assailant and others with ulterior motives had "rapidly decided that something was suspicious. That I was lying. That the perpetrator was innocent", she wrote.
"One strange story after another was brought up in a gigantic court of public opinion with anonymous judges and witnesses who guessed wildly," she added.
The woman, who is politically active, said she received threats and was forced to go underground. But after a while, people also began to stand up for her.
"Maybe someone would have acted upon one of all the threats I received. Maybe I would have had to change my name and move away, and I would probably have been considered someone on whom you lose both elections and clients, which would have made it impossible for me to be both involved [politically] and work, other than the few months I had to go underground."
In the blogpost, published in mid-April but only reported in the Swedish media on Thursday, the woman did not identify Assange by name but the timing of her account is in line with the sex crime allegations brought against him.
The two women accused the Australian activist of rape and sexual assault in 2010, when he was in Stockholm on WikiLeaks business.
Assange has denied the accusations, arguing they are part of a smear campaign to discredit his whistleblowing website.
He is wanted for questioning in Sweden, but has been holed up in the Ecuadorian embassy in London since June 2012 after he was granted asylum but denied free passage by British authorities out of the country.
Assange fears that if he is handed over to Sweden he will be passed onto the United States for his controversial diplomatic memo leaks.