WASHINGTON – A lawyer for a former government nuclear scientist, Wen Ho Lee, yesterday argued in federal appeals court that Mr. Lee’s right to sue the government should trump journalists’ privilege to protect their sources, a claim lawyers for the journalists involved in Mr. Lee’s case hotly contested.

Mr. Lee is suing the federal government under the federal Privacy Act over leaks related to an espionage investigation that targeted him in the late 1990s. The case, while a civil lawsuit rather than a criminal probe, is similar to the reporters’ privilege arguments in the case involving Valerie Plame, a former undercover CIA operative who was identified in news reports.

In the Lee case, a lower court cited five journalists for contempt after they refused to reveal their sources for articles that Mr. Lee alleged violated the privacy law. A three-judge panel of the U.S. Circuit Court of the District of Columbia yesterday heard arguments in the journalists’ appeal.

The argument hinged on whether Mr. Lee had exhausted all other possible sources of information about the origin of the leaks. The lower court judge found the reporters were the only remaining sources for information about the leaks and held them in contempt when they refused to answer questions from Mr. Lee’s lawyers in depositions last year.

Floyd Abrams, an attorney representing Jeff Gerth and James Risen of the New York Times, argued that reporters’ privilege should be protected because Mr. Lee still has other ways of finding the source of the leaks.

“There are a large number of individuals who have knowledge of the matters involved in this case” but who have not yet been deposed, Mr. Abrams said.

Mr. Lee’s lawyer, Brian Sun, disputed that claim, saying he and his colleagues tried “every which way to Sunday” to determine the sources in at least 20 depositions with government employees.

Judge A. Raymond Randolph was the most pointed of the appeals judges in his questioning of the attorneys, questioning whether the case would have a future chilling effect on the willingness of sources to speak to reporters.

“If you narrow the case to the Privacy Act, the impact [of breaching the privilege] would be that government officials would stop violating the Privacy Act,” Judge Randolph said during Mr. Abrams’s argument.

A lawyer for Pierre Thomas, formerly of CNN and now at ABC News, argued that Mr. Lee’s attorneys had failed to properly depose witnesses in the case.

“The right questions must be asked [of witnesses] before we can say they’ve been exhausted,” Mr. Pierre’s lawyer, Charles D. Tobin said. “They didn’t even fatigue” two of five witnesses who testified regarding Mr. Pierre, Mr. Tobin said.

Mr. Sun said that what might have appeared to be softball questioning in the deposition transcripts was actually part of a carefully planned strategy to obtain as much testimony as possible. “We did what we thought was reasonable to get information from sources other than journalists,” he said.

Lee Levine, an attorney for Bob Drogin of the Los Angeles Times and H. Josef Hebert of the Associated Press, argued that District Court Judge Thomas P. Jackson erred in citing those reporters for contempt before holding a hearing to determine whether information obtained from their sources violated the Privacy Act in the first place.

It was not immediately clear how a ruling in this case could affect the separate contempt proceedings against two reporters in the Plame case. A separate three-judge panel of the same appeals court ruled that a federal prosecutor could compel journalists to testify in that criminal case.

New York Times reporter Judith Miller and Time reporter Matthew Cooper have been called to testify about their sources of information on the identity of Ms. Plame before a criminal grand jury.

“The fact situation is a bit different in this case, but the overall picture is the same,” said Paul McMasters of the First Amendment Center.

Courts have traditionally applied a “sliding scale” when considering whether to compel reporters’ testimony, said a professor at the Silha Center for the Study of Media Ethics and Law at the University of Minnesota, Jane Kirtley. Criminal cases in which journalists are called as defense witnesses are the hardest for reporters to win, Ms. Kirtley said. The court might decide that not enough is at stake in a civil suit to warrant breaching journalistic privilege.

The judges in the Lee case could opt to draw a bright line between the standard set in the Plame case and the standard it would set in this civil proceeding, Ms. Kirtley said.

Mr. McMasters said this case was likely to have some effect on the Plame case. “Symbolically, [the] outcome would be important,” Mr. McMasters said, since reporters are under increasing pressure to disclose sources.