High-profile attorney Michael Avenatti tells Chicago Tribune he believes charges are imminent against R. Kelly after giving Cook County prosecutors a tape purportedly depicting the R&B musician having sex with an underage girl.

Avenatti spoke to reporters after he and a high-level Cook County assistant state’s attorney were spotted leaving the county’s main criminal courthouse Friday afternoon.

“I’m not at liberty to get into the details of the time that I’ve spent here today and what’s transpired,” he said in the lobby of the Leighton Criminal Court Building. “But needless to say, I’m confident that the predator known as Robert Kelly is soon to be indicted and charged for engaging in an illegal sexual assault in connection with, certainly, the victim on the tape that I supplied, as well as others.”

The Cook County state’s attorney’s office did not immediately respond to a request for comment Friday. A spokeswoman said Thursday the office could not confirm or deny an investigation.

Avenatti said he gave prosecutors the tape earlier this month. He declined to give specifics about when Kelly might be charged or with what crimes.

The video appears to have been made in the late 1990s in Chicago, he told the Tribune earlier this week. It apparently was filmed at a residence of R. Kelly’s, though not his Near West Side studio, he said. He did not release information on the victim in the video because she was a minor at the time.

“I don’t believe that R. Kelly should ever walk free another day in his life due to the conduct that’s depicted on that videotape,” he said Friday. “This guy’s a predator, he’s a sexual abuser of young girls, and he deserves to spend the rest of his life in prison.”

Kelly’s attorney, Steve Greenberg, has consistently denied allegations of wrongdoing.

“If R. Kelly is charged with anything, we will address it in court, and I am confident he will leave through the front door,” he told the Tribune on Friday.

CNN reported that it has seen the tape. It quoted Avenatti as saying that his client “knows the identity of the girl and R. Kelly. He identified the two of them on the videotape. He worked for and has known R. Kelly for decades and he met the girl on a number of occasions.”

The New Yorker and other media outlets also reported on the surfacing of the tape.

Avenatti’s claim comes about a month after State’s Attorney Kim Foxx called on any accusers of R. Kelly to come forward, citing “deeply, deeply disturbing” allegations in a documentary series detailing long-standing accusations of sexual misconduct against the singer.

The six-hour documentary, “Surviving R. Kelly,” aired on the Lifetime channel and alleged that he has manipulated young women into joining a sex cult.