When Jim Stewart stepped down from CBS News in November 2006 after some 16 years of reporting on a range of topics for the Tiffany Network, the longtime Washington-based correspondent retired to the warmth of Florida. Now, depending on a judge’s ruling in an ongoing case, Mr. Stewart could be spending a part of his golden years in a much less sunny position—namely in contempt of a federal court.

In legal documents filed on the eve of the holidays, Mr. Stewart, citing promises of confidentiality, continued to defy a judge’s order to reveal the names of his sources for a series of reports he produced in 2003 for CBS News about the F.B.I.’s investigation into the domestic anthrax attacks of 2001.

If U.S. District Judge Reggie Walton decides in the coming months to hold Mr. Stewart in civil contempt for his defiance, the case, which lately has been unfolding largely under the news radar, could become one of the more tortured—and high-profile—media soap operas of the new year.

And, in the wake of the Valerie Plame affair, in which The New York Times’ Judith Miller served jail time for her own refusal to give up sources, it could offer additional ammunition to advocates of a federal shield law—which would increase journalists’ legal right to protect their sources in court. Norman Pearlstine, the former editor in chief of Time Inc. who earlier this year wrote a book about confidential sources, media law and his pivotal role in the Valerie Plame affair, told NYTV that Mr. Stewart’s case “is a perfect example of why we need a federal shield law.”

Some back story: In the summer of 2002, Attorney General John Ashcroft named Steven Hatfill, a former government scientist, as a “person of interest” in the government’s criminal investigation into the anthrax attacks. Roughly a year later, Mr. Hatfill filed a civil lawsuit alleging that by talking about him to reporters, FBI and DOJ staffers had violated his rights under the federal Privacy Act—a 1974 law that restricts the public disclosure of certain information about government employees.

Over the course of several months in the summer of 2003, Mr. Stewart, who was then covering counterterrorism for CBS News, produced three Evening News reports about the investigation and the FBI’s ongoing surveillance of Mr. Hatfill, whom many authorities considered to be a top suspect. According to court documents, Mr. Stewart’s reporting relied, in part, on four confidential sources at the F.B.I.

Fast-forward four years. This past August, with Mr. Hatfill’s lawsuit still unresolved, Judge Walton ruled that Mr. Stewart and a handful of other reporters who had covered the story—including Michael Isikoff and Daniel Klaidman of Newsweek, Brian Ross of ABC News, Allan Lengel of The Washington Post, and Toni Locy of USA Today—would be required to turn over the names of their sources.

When deposed this past September, Mr. Stewart declined to do so. (All the other reporters except Ms. Locy were apparently released by their sources from their pledges of confidentiality. Ms. Locy claimed in her deposition not to remember the names of her sources.) In response, Mr. Hatfill’s lawyers, who did not return phone calls from NYTV seeking comment, filed a motion to hold Mr. Stewart in contempt of court.

The contempt motion argued that Mr. Stewart’s “entrenched defiance” called for escalating fines, starting at $1,000 per day. And it added: “The risk of industry support for Mr. Stewart’s contempt calls for one additional measure: the Court should prohibit Mr. Stewart’s solicitation or acceptance of any reimbursement for any contempt fines it should levy.”

Just before Christmas, Mr. Stewart responded to the motion for contempt. In extensive court filings, he explained that he had reached out to three of his four F.B.I. sources, only one of whom had agreed to be named. That source, a former F.B.I. public affairs specialist named Edwin Cogswell, had previously been contacted by other reporters in the case and in due course had essentially outed himself.

Mr. Stewart’s legal team went on to argue that because of intervening developments—specifically, the fact that Mr. Cogswell and two other former F.B.I. and Department of Justice employees have come forward as reporters’ sources—the judge should reconsider his initial ruling compelling Mr. Stewart to identify his sources. Mr. Stewart’s lawyer, Lee Levine, declined to comment on behalf of his client.

CBS appears to have largely extricated itself from the affair. Last May, it quashed an effort by Mr. Hatfill’s lawyers to subpoena CBS Broadcasting Inc. A CBS spokesperson declined to comment on the case.

The case has some parallels to that of Dr. Wen Ho Lee, a former government scientist at the Los Alamos nuclear laboratory who had been accused of sharing classified nuclear information with China, and who subsequently sued the federal government under the Privacy Act. In the suit, Mr. Lee’s lawyers similarly subpoenaed six reporters, seeking the identities of their confidential sources in the government. The judge in the case ordered the reporters to testify, but the case came to an end before they did so when Mr. Lee settled with the government.

In Off the Record: The Press, the Government, and the War over Anonymous Sources, Mr. Pearlstine wrote that the Wen Ho Lee settlement would encourage “plaintiffs in other Privacy Act lawsuits against the government to seek testimony from the media whenever leaks from confidential sources are involved.”

And to some media-rights advocates, that appears to have happened, creating concern about reporters’ ongoing ability to credibly promise confidentiality to sources. “The [Privacy] Act was intended to cover such private information as medical data, psychiatric history and employment details,” Sandra Baron of the Media Law Resource Center told NYTV. “To the extent that this would mean that someone who is a suspect in an investigation can’t be reported on, I think that’s outrageous and unacceptable.” Ms. Baron called the pressure put on reporters to give up their confidential sources “a very ugly and very invasive side effect of these Privacy Act claims.”

Whether Mr. Stewart will become the next poster child for the cause depends, for now, on Judge Walton.