Chicago Sun-Times music critic Jim DeRogatis must testify for the defense in┬áR. Kelly’s child porn trial, a judge ruled Friday.

In a ruling that legal experts say could have wide-ranging implications for the freedom of the press, Judge Vincent Gaughan said DeRogatis has no constitutional protection or “reporter’s privilege” against testifying.

DeRogatis broke the story of the notorious sex tape at the heart of Kelly’s trial in 2002 and passed a copy of the tape to police, sparking the investigation that led to Kelly’s arrest.

Kelly denies taping himself having sex with his “goddaughter” when she was just 13- or 14-years old. He faces up to 15 years behind bars if convicted.

Gaughan said Kelly’s attorneys will be allowed to question DeRogatis about when he received the tape and what he did with it before turning it over to police. But the judge said they cannot ask whether he made a copy or ask any questions about his sources.

According to evidence already heard at trial, an anonymous tipster left the tape in DeRogatis’ mailbox.

Kelly attorney Marc Martin said DeRogatis’ testimony is “crucial” to the singer’s defense, arguing that the reporter was the first person known to possess the tape and accusing DeRogatis of “extreme bias” against Kelly.

Martin said the defense team also expects DeRogatis to undermine the testimony of Stephanie “Sparkle” Edwards, a relative of the alleged victim who identified Kelly and the alleged victim on the tape.

But Sun-Times attorney Damon Dunn argued in court that DeRogatis could say nothing that would help Kelly, adding that forcing the reporter to take the stand would have a wider “chilling effect” on whistleblowers contacting the media.

Dunn said the Illinois reporter’s privilege and the First Amendment both protected DeRogatis from testifying, adding that “whether or not Mr. DeRogatis harbors bias against pedophiles is neither here nor there.”

Siding with Kelly’s attorneys, Gaughan said that DeRogatis must testify.

The reporter’s privilege protects journalists only from revealing their sources, he said, ordering DeRogatis to hand over notes of an interview with Edwards.

Dunn said DeRogatis would appeal the judge’s decision.

Speaking after the ruling Friday, several media law experts said the ruling further confused already complex laws protecting reporters and their sources.

Jane Kirtley, a professor at the University of Minnesota, said it was a “pretty bizarre chapter in a bizarre case.”

She added, “The message that this sends journalists who cover these sorts of stories is that they do so at their own risk.”

Don Craven, a First Amendment expert who often represents the media, said the ruling would “discourage people with information that the public should have from coming forward and speaking to reporters.”

The trial is set to resume Monday, when the repeatedly delayed testimony of Lisa Van Allen — an Atlanta woman who says she had three-way sex with Kelly and the alleged victim — could finally take place.