A former Army scientist once identified as a "person of interest" in the deadly 2001 anthrax attacks shouldn't be considered a public figure in his libel lawsuit against The New York Times, his lawyer argued Friday before a federal appeals court.

Steven J. Hatfill said a series of columns in The Times falsely implicated him as the culprit in the anthrax deaths. No one has been charged.

In a ruling last year, U.S. District Judge Claude M. Hilton said Hatfill could be considered a public figure, making it more difficult to win a judgment, because he had been part of the national debate about bioterrorism years before the anthrax attacks.

Hatfill had occasionally been quoted as an expert in the media, and even once donned a chemical suit for a magazine photo.

Hatfill, who worked at the Army's infectious diseases laboratory from 1997 to 1999, was publicly identified as "a person of interest" in the investigation by then-Attorney General John Ashcroft.

Hatfill's attorney told a three-judge panel of the 4th U.S. Circuit Court of Appeals on Friday that Hatfill hadn't injected himself into the debate following the 2001 incidents.

"There's simply no thrusting by Dr. Hatfill," Christopher Wright told the court.

But Times lawyer Lee Levine said Hatfill for years was speaking out about how easy it was "to cook up" anthrax or the plague in his kitchen, qualifying him as a public figure.

Still Wright pointed to flaws in the reporting of columnist Nicholas Kristof, saying he didn't contact Hatfill because he believed Hatfill wasn't talking to the press.

"In the situation when you're making extremely damaging accusations ... he should have called him," Wright said.

Kristof has said he never intended to accuse Hatfill but simply wanted to prod what he saw as a dawdling FBI investigation.

He initially referred to Hatfill in his columns only as "Mr. Z," and identified him by name only after Hatfill held a news conference to denounce rumors that had been swirling around him.

Five people were killed and 17 sickened when anthrax was mailed to lawmakers on Capitol Hill and members of the news media in New York and Florida just weeks after the Sept. 11, 2001, terrorist attacks.