The 38-year-old woman, who has not been identified, spoke with detectives from the Los Angeles Police Department's sexual assault unit on Thursday, her attorney Dave Ring told reporters at a news conference Friday.
Ring said the LAPD conducted a "thorough interview," in which his client told detectives what happened in that hotel room "in graphic detail."
"While I'm not able to get into the details of what she shared with the detectives...it's my understanding that caused the LAPD to open up a criminal investigation for sexual assault and rape," Ring said.
MORE: Harvey Weinstein under investigation by LAPD for alleged 2013 sexual assault
Ring said his client was 34 at the time of the alleged incident and was working as an actress in Italy. She was in Los Angeles to attend the L.A. Italia Film Festival in February 2013.
She had met Weinstein once very briefly in Rome. She then met him a second time at the L.A. Italia Film Festival and had a very brief conversation with him, Ring said.
"That evening, Weinstein appeared at her hotel, which is just outside the city limits of Beverly Hills, and he basically bullied his way up into her room," Ring said. "She has told me that obviously her greatest regret is opening that door."
MORE: Lupita Nyong'o gives vivid account of Weinstein's alleged abuses
Ring mentioned the incident reported by The New Yorker about a sting operation conducted by the New York Police Department in 2015.
"If you've heard the audio tape...with the female in the New York City incident that the police had her wear a wire and recorded that conversation, you know exactly what I'm talking about when I say he bullied his way into her room," Ring said.
He said the other women who came forward about their experiences helped his client come forward.
"There is strength in numbers. When you hear other people saying, 'that happened to me,' that gives a lot of courage," Ring said. "Whoever that first person was that came forward, that is an incredibly courageous person."
MORE: "Me Too" movement furthers talks about sex assault in social media
Also Friday, a former television and stage actress came forward to accuse Weinstein of exposing himself to her during a meeting in 1989.
Heather Kerr spoke at a news conference alongside her attorney, Gloria Allred. Kerr said she had been working in the office of an entertainment business manager and sometimes answered the phones.
Weinstein was a frequent caller and at one point, he suggested they meet at an office in Westwood, Kerr said.
After she arrived, he told her to sit on the couch, sat next to her and kept telling her she needed to be "good" if she wanted to succeed. He then pulled down his zipper and exposed himself.
Kerr says she backed away from him, left the room and hurried out of the building. After some theater work, she quit acting.
"I felt so powerless," she tearfully recalled. Her acting credits in the 1980s include the TV shows "The Facts of Life" and "Mama's Family."
Weinstein is facing criminal charges in three cities after allegations of rape and sexual assault.
He has recently been accused of multiple acts of sexual harassment and assault spanning decades. He has been fired from The Weinstein Co., a TV and movie film production company he co-founded with his brother Bob. He already has been expelled from the Academy of Motion Picture Arts and Sciences, the Producers Guild and the British Academy of Film and Television Arts.
His representative has denied the Oscar-winner had non-consensual sex with any woman.
The Associated Press contributed to this report.