A woman who sued William Kennedy Smith (search) said Thursday that the member of the prominent political family sexually assaulted her five years ago "in a manner that will haunt me to the day I die."

"Today I am putting William Kennedy Smith on notice. You will not victimize another woman and be able to keep it silent if I can help it," Audra Soulias said at a news conference.

Smith denies the allegations and claims she filed her civil lawsuit only after he refused to pay $3 million. The 43-year-old Kennedy cousin said his "family and personal history have made me unusually vulnerable to these kinds of charges," and he calls the accusations "outrageous, untrue and without merit."

Soulias said the power and money held by Smith's family was what kept her silent for five years, although her lawyer acknowledged that the woman had consensual sex with Smith several times after the encounter. The attorney said such behavior was typical in cases of "acquaintance rape."

In 1991, a jury in West Palm Beach, Fla., acquitted Smith of sexual assault and battery on a woman he met in a nightclub. He said the sex between him and the accuser had been consensual.

Smith's mother is former U.S. Ambassador to Ireland Jean Kennedy Smith (search). He is the nephew of Sen. Edward Kennedy (search) of Massachusetts and the late President Kennedy.

Soulias, 28, who formerly worked for Smith, said in a lawsuit filed Wednesday that he assaulted her in his bedroom in 1999 after buying her a number of drinks during a night on the town with friends to celebrate her birthday.

After she was drunk, Soulias said Smith took her by cab to his home, dragged her inside, and assaulted her. Soulias attorney Kevin O'Reilly said the alleged assault consisted of "digital penetration" against his client's will.

"On Jan. 16, 1999, my innocence was involuntarily taken from me by someone I trusted and respected," Soulias said in a quavering voice. "It was taken from me in a manner that will haunt me to the day I die."

Soulias is seeking at least $50,000 -- the minimum amount lawyers must seek in such suits in Illinois. The lawsuit alleges she has suffered "great physical and emotional pain and discomfort" and "a permanently impaired earning capacity."

O'Reilly said she took her story to prosecutors two years ago but that they believed it would be too hard to prove.