Kelly entered a not guilty plea Monday in response to being charged with 10 counts of aggravated criminal sexual abuse. She contacted Kelly, who told her to take a cab to his studio, where they had sex periodically for a year, the documents said. Avenatti previously gave prosecutors a video he said showed Kelly having sex with an underage girl.
Prosecutors allege Kelly sexually abused his hairdresser while he was free on bond on then-pending child pornography charges.
Kelly spent the weekend in Cook County Jail, after another judge set his bail at $1 million on Saturday. Kelly's lawyer says the singer's finances are "a mess", as Kelly has been unable to come up with the money to bail out and has been behind bars since Friday night.
"This is someone who should be wealthy at this stage of his career", Kelly's attorney Steve Greenberg said, citing "bad deals" hangers-on" and "bad deals" as the source of his financial woes.
His next court appearance was set for March 22.
After a dramatic trial, he was acquitted in 2008 of charges of child pornography, also in Chicago.
Los Angeles-based lawyer Gloria Allred said she represents six women who have come forward to accuse Kelly of sexual abuse, including some who were featured in the documentary. The allegations date back as far as 1998 and span more than a decade.
A witness reported having spoken to Kelly and his associates in 2001 and was instructed to recover videotapes that showed Kelly having sex with the alleged victim when she was 14 years old, prosecutors contend.
Posting to her 77.6m followers, Gaga said: "I stand behind these women 100%, believe them, know they are suffering and in pain, and feel strongly that their voices should be heard and taken seriously".
At least four law enforcement agencies outside Cook County have opened investigations into her clients' complaints, Allred told a news conference on Monday, including the New York Police Department and federal prosecutors in Brooklyn.
In early 2003, a Chicago hairdresser told prosecutors that she thought she was going to braid Kelly's hair, but he pulled down his trousers and instead tried to force her to give him oral sex.
Aggravated criminal sexual abuse is a Class 2 felony with a sentencing range of 3-7 years in prison.
"He's a rock star".
Kelly faced similar charges in 2008 but was aquitted. "He doesn't have to have nonconsensual sex", according to the AP.
She also stated that one of the victims had given authorities a shirt that she wore during the incident which tested positive for the singer's DNA. Probation is also an option.