Attorney Michael Avenatti said his office has been “quietly” investigating allegations made against embattled singer R. Kelly and has turned over “significant new evidence conclusively establishing Mr. Kelly’s illegal sexual assault of young girls.”

Avenatti confirmed Thursday that his office gave a VHS videotape to Cook County State’s Attorney Kim Foxx that allegedly features R. Kelly and “has never previously been publicly disclosed or, until recently, provided to law enforcement.” The roughly 45-minutes of footage purportedly shows Kelly “engaging in multiple sexual assaults of a girl underage,” Avenatti said.

“This conclusive video evidence is not the same evidence previously seen and used in connection with the prior criminal matter in which Mr. Kelly was charged nor does it depict the same instances of sexual assault,” Avenatti wrote in a statement. “Further, the time frame of the sexual assaults depicted in the video is within the Illinois statute of limitations.”

Foxx’s office said it “cannot confirm or deny an investigation,” though Foxx had previously called on potential victims to come forward.

Kelly’s attorney, Steve Greenberg, said he was not aware of the video before Avenatti's announcement.

"I have not been contacted by anyone connected with law enforcement, nor has R Kelly," Greenberg wrote in a statement. "Mr. Kelly denies that he has engaged in any illegal conduct, of any kind whatsoever. He would like to be able to continue to write and sing and produce and perform."

CNN reported it has seen the videotape and reporter Jim DeRogatis, who has been covering Kelly for more than a decade, wrote in the New Yorker that a senior law enforcement official indicated the footage could lead to an indictment in the case.

"If the video were what it is claimed to be, by sharing it with CNN Mr. Avenatti would be committing a felony, as would the reporter who viewed it," Greenberg's statement read. "I doubt if either would put themselves in that position. That combined with the other facts that I know lead me to question the reports."

Kelly has been under fire since the airing of the Lifetime docuseries "Surviving R. Kelly." NBC 5 Investigates also recently obtained police documents detailing allegations from a woman who said she was abused by Kelly as a teenager.

Kelly has denied all allegations of sexual misconduct involving women and underage girls.

Avenatti, who also represents porn actress Stormy Daniels in her lawsuits against President Donald Trump, said his office was retained by multiple clients in April 2018 in connection with allegations of sexual assault of minors by Kelly.

He said his office will “continue to cooperate” with Foxx.