Chris Brown sued over alleged sexual battery, assault at his home An young woman, known as Jane Doe, claims she was raped at the singer's home.

A woman is suing Chris Brown and several members of his entourage alleging she was the victim of sexual battery, assault and gender violence at a party at the rapper's home, according to a lawsuit filed on her behalf by attorney Gloria Allred.

In the suit, which was filed Wednesday in Los Angeles County Superior Court and obtained by ABC News, the woman is listed only as Jane Doe. She alleged the Brown's friend Lowell Grissom Jr. (Young Lo), raped her twice at Brown's home in February 2017.

Brown's attorney, Mark Geragos, denied the allegations in an interview with TMZ, adding that Doe originally demanded $17 million from the singer.

"In another era we might've called this a shakedown," he said. "Chris didn't do anything and they know Chris didn't do anything. Other than using his name so that she could have a press conference, I don't understand why he's dragged into anything."

Geragos did not immediately respond to a request for comment; ABC News has been unable to locate a representative for Grissom Jr.

The Los Angeles Police Department confirmed to ABC News that there is an open investigation regarding Grissom Jr. that has been referred to the district attorney's office. The Los Angeles D.A. did not immediately respond to a request for comment from ABC News.

"This is one of the most horrific cases involving alleged sexual assaults that I have ever seen, and our client, Jane Doe, has been severely traumatized by what she was forced to suffer," Allred stated Wednesday during a press conference. "She filed this lawsuit because she wants justice for herself, but she also wants to warn other young women about the potential danger to themselves if they have their phone taken away and if they go to Chris Brown’s house.

"She does not want any other young woman to endure the violent sexual assaults that she was forced to endure in an environment of guns and drugs. We look forward to our client having the opportunity to have her day in court. We want to hold accountable those who were responsible for the gender violence inflicted upon her."

According to the lawsuit, after attending a Brown concert at a club, Doe went to an after party at a music studio, during which her cell phone was confiscated. Grissom Jr. allegedly refused to return the phone and told her that the group was moving to Brown's home. Doe claims she went, hoping to retrieve her phone there.

At the house, according to the lawsuit, the group began consuming alcohol and drugs, and Doe claims that Brown gave each female guest a pill and instructed them to take it to have a "good time." She refused, according to court papers.

Meanwhile, Doe's mother, who grew anxious after being unable to contact her daughter, tracked the location of Doe's phone and asked the police to go there, the lawsuit states. Brown, who, according to the lawsuit, allegedly asked Grissom Jr. and others to hide a duffel bag full of firearms, refused to allow detectives onto the property.

"After the police left the area, Brown continued to supply his guests with drugs and alcohol. Plaintiff observed him carrying one gun in his waistband and brandishing it openly. She saw him wave it in the air, which further frightened and intimidated Plaintiff," the lawsuit reads. "Whenever Plaintiff asked Grissom to return her phone, he was evasive and failed to return it to her."

Doe claims that after that, she was repeatedly assaulted. After she was able to extricate herself from Brown's home, she said she went to a rape treatment center and reported her claims to the police, according to the suit.

ABC News' Andrea Dresdale contributed to this report.