Disgraced comedian Bill Cosby was dealt another blow Monday when the U.S. Supreme Court denied review of his appeal in a California defamation case brought by one of Cosby's alleged rape victims.

The case Cosby v. Dickinson challenged a California Court of Appeal decision that said a defamation lawsuit brought by Janice Dickinson against Cosby and his onetime lawyer Martin Singer of Lavely & Singer could go forward in spite of precedents that protect the speech of lawyers who speak out on behalf of their clients.

Singer was dismissed from the suit, but the California ruling may have ramifications for lawyers' free speech rights.

In 2014, Dickinson accused Cosby of raping her, and Singer issued a statement denying the accusation and pointing out previous contradictory statements she had made.

In a petition to the high court, Sarah Kelly-Kilgore of Greenberg Gross, counsel of record for Cosby, cited the 1991 Supreme Court case Gentile v. State Bar of Nevada, in which Justice Anthony Kennedy wrote that a lawyer “may take reasonable steps to defend a client's reputation … including an attempt to demonstrate in the court of public opinion that the client does not deserve to be tried.”

The California court ignored that principle in its decision, Kelly-Kilgore said in her petition and “will improperly chill attorneys' speech and prevent any person—the innocent along with the guilty—from relying upon his or her attorney to respond to public accusations of misconduct.”

She also asserted that “if the California court's decision is allowed to stand, attorneys will be faced with an impossible choice: either provide a swift and decisive response to accusations against a client, thereby placing both the attorney and client at risk of a defamation suit; or remain mute in the face of highly publicized accusations, and risk the devastating harm to the client that flows from leaving such accusations unanswered.”

The California Supreme Court denied review, setting the stage for an appeal to the U.S. Supreme Court.

Kelly-Kilgore pointed out that, in similar Cosby-related defamation cases, the U.S. Courts of Appeals for the First and Third circuits ruled that Singer's statements were protected under the First Amendment, and the cases were dismissed. One of those cases, McKee v. Cosby, was appealed to the U.S. Supreme Court and is still pending.

Alan Greenberg of Greenberg Gross, a lawyer for Cosby, said in a statement Monday:

“The litigation continues in state court and may come back to the Supreme Court in a different procedural posture. There is a critical issue of freedom of speech at stake. Attorneys and their clients must not be subjected to collateral litigation simply because they issue public denials of public allegations.”

Cosby was sentenced last week in Pennsylvania to three to 10 years in prison on charges of aggravated indecent assault stemming from claims he drugged and sexually assaulted a woman in 2004. Cosby's lawyers have vowed to appeal the conviction and sentence.

Read more: