Dickinson, now 59, recalls first meeting Cosby, now 77, when her agent set up a meeting with him to hire her for a role on The Cosby Show. After they had dinner, she says their next conversation was when he called her out of the blue while she was in rehab for drugs and alcohol. Following her stay in rehab, Dickinson says Cosby reached out to her during a trip to Bali and had her travel to Lake Tahoe, because he was performing there and wanted to offer her the job they had discussed as well as help her with a singing career.
Dickinson says they had dinner in Lake Tahoe, and claims that he gave her a glass of red wine and a pill, which she asked for because she was menstruating and had stomach pains.
And that's when she tells ET that things took a disturbing turn.
"The next morning I woke up, and I wasn't wearing my pajamas, and I remember before I passed out that I had been sexually assaulted by this man," she tells ET. "... Before I woke up in the morning, the last thing I remember was Bill Cosby in a patchwork robe, dropping his robe and getting on top of me. And I remember a lot of pain. The next morning I remember waking up with my pajamas off and there was semen in between my legs."
Dickinson also says she tried to write about the assault in her 2002 autobiography No Lifeguard on Duty: The Accidental Life of the World's First Supermodel, but claims that when she submitted a draft with her full story to HarperCollins, Cosby and his lawyers pressured her and the publisher to remove the details.
"I'm doing this because it's the right thing to do, and it happened to me, and this is the true story," she says about coming out with her story now. "I believe all the other women."
Dickinson says that keeping the alleged sexual assault a secret for 32 years drove her to a life of hurting herself.
"Stuffing feelings of rape and my unresolved issued with this incident has drove me into a life of trying to hurt myself because I didn't have counsel and I was afraid," she says. "I was afraid of the consequences. I was afraid of being labeled a whore or a slut and trying to sleep my way to the top of a career that never took place."
But now Dickinson, who says she never confronted Cosby after the alleged incident, doesn't mince words when it comes to what she would say to him now.
"How dare you," she says. "Go f*ck yourself. How dare you take advantage of me. And I hope you rot."
Dickinson is the third woman to come forward with a sexual assault accusation against Cosby, after a renewed interest in the allegations began when comedian Hannibal Buress called Cosby a "rapist" during an October comedy show in Philadelphia.
On Monday, ET spoke to former publicist Joan Tarshis who says that the legendary comedian assaulted her on two occasions in 1969. She also echoed Dickinson's statements about why she stayed silent for so long.
"I want to talk about this now and I want to really support the other women who have gone through this," she told ET. "Now with people coming out..., it's being handled differently."
Tarshis is referring to another of Cosby's accusers, Barbara Bowman, who wrote an op-ed piece in the Washington Post earlier this month detailing the alleged assault she says she fell victim to in 1985 when she was a 17-year-old aspiring actress.
"In one case, I blacked out after having dinner and one glass of wine at his New York City brownstone, where he had offered to mentor me and discuss the entertainment industry," she wrote. "When I came to, I was in my panties and a man's t-shirt, and Cosby was looming over me. I’m certain now that he drugged and raped me. But as a teenager, I tried to convince myself I had imagined it."
Bowman said that she was one of the alleged victims asked to testify when a woman named Andrea Constand filed a suit against Cosby in 2004. The case was eventually settled out of court.
Cosby's lawyer, John P. Schmitt, issued a statement on Sunday in response to the sexual assault allegations after Cosby's initial response of just silence during an NPR interview Saturday.
"Over the last several weeks, decade-old, discredited allegations against Mr. Cosby have resurfaced. The fact they are being repeated does not make them true," the statement reads. "Mr. Cosby does not intend to dignify these allegations with any comment. He would like to thank all his fans for the outpouring of support and assure them that, at age 77, he is doing his best work. There will be no further statement from Mr. Cosby or any of his representatives."