WASHINGTON – A recent barrage of attacks on the credibility of a New York Times reporter, Judith Miller, could affect a prosecutor’s decision about whether to bring indictments of White House officials in an investigation of the leak of a CIA operative’s identity, according to legal analysts.

Attorneys closely following the case said the sharp criticism Ms. Miller has received from her editors and colleagues may discourage the prosecutor, Patrick Fitzgerald, from bringing perjury charges against Vice President Cheney’s chief of staff, I. Lewis Libby.

According to Ms. Miller and others who have testified before the grand jury investigating the leak, Mr. Fitzgerald has shown significant interest in whether Mr. Libby or other White House officials testified truthfully about their involvement in an alleged effort to discredit a vocal critic of President Bush, Joseph Wilson IV, by disclosing that his wife is a CIA employee.

The prosecutor’s intense interest in Mr. Libby may be related to an alleged discrepancy about how he came to learn that Mr. Wilson’s wife worked at the CIA. Mr. Libby has reportedly testified that he learned of the link from journalists, but the Times reported on its Web site last night that the White House aide’s own notes – obtained by Mr. Fitzgerald – indicate that Mr. Libby learned of the connection from Mr. Cheney on June 12, 2003, more than a month before the CIA operative’s name appeared in the press.

The notes do not indicate that Mr. Cheney or Mr. Libby knew that the operative, Valerie Plame, was considered to be undercover by the CIA, the Times said. However, the prosecutor may view Mr. Libby’s alleged failure to disclose the contact with Mr. Cheney as an illegal effort to stymie the investigation.

“If it’s going to be a perjury case, he’s got a hard case because his key witness is Judy Miller,” a former federal prosecutor, Paul Rosenzweig, said. “She has some issues as a witness.”

Last week, the Times published a lengthy story containing unflattering anecdotes about Ms. Miller, including a claim that she referred to herself as

“Miss Run Amok.” On Friday, the newspaper’s managing editor, Bill Keller, sent a memo to his staff asserting that Ms. Miller “seems to have misled” the paper’s Washington bureau chief, Philip Taubman, regarding her knowledge about Mr. Libby’s alleged campaign against Mr. Wilson. On Saturday, a Times columnist, Maureen Dowd, questioned Ms. Miller’s candor and suggested that she no longer be allowed to write for the newspaper.

Mr. Rosenzweig, who worked on the independent counsel investigation of President Clinton, said the attacks on Ms. Miller would complicate any attempt to present her as a witness. “Can you imagine a defense attorney saying, ‘So, I understand they call you Miss Run Amok?'” the ex-prosecutor said.

A law professor at George Washington University, Jonathan Turley, said the storm surrounding Ms. Miller adds a layer of complexity to Mr. Fitzgerald’s decision about how to proceed.

“The government is used to dealing with conflicted and questionable witnesses in the form of mob informants and drug dealers. They don’t normally expect to have to rehabilitate a New York Times reporter,” Mr. Turley said. “She would present a target-rich environment for cross-examination.”

A spokesman for Mr. Fitzgerald, Randall Samborn, declined to be interviewed for this story.

In a brief interview last night, Ms. Miller said it was difficult for her to assess how the very public battle over her conduct might impact Mr. Fitzgerald’s plans. “I just don’t know,” she said.

In a note posted Sunday on the Times’s Web site, Ms. Miller referred to Mr. Keller’s memo as “ugly” and “inaccurate.” In a separate e-mail to her colleagues last week, she attempted to rebut some of the allegations against her, but also said she was holding back some details about her involvement because she might be put on the stand by Mr. Fitzgerald. “Since I could be [a] witness at a future trial, I am reluctant to say more on this subject now,” Ms. Miller wrote.

While some Republicans, such as Senator Hutchison of Texas, have suggested in recent days that Mr. Fitzgerald is delving into trivialities by considering perjury and obstruction of justice charges, President Bush indicated yesterday that he still views the inquiry as an important matter.

“This is a very serious investigation,” Mr. Bush said at a Cabinet meeting attended by Mr. Libby and another top official who has testified repeatedly before the grand jury, Karl Rove. The president, who addressed the issue only in response to a reporter’s question, said he would not discuss the matter further until the inquiry is complete. The grand jury investigating the case is scheduled to end its work on Friday, unless the prosecutor seeks an extension.

Mr. Libby’s attorney has declined interview requests. Through his lawyer, Mr. Rove has denied any wrongdoing.

An attorney who prosecuted terrorism cases with Mr. Fitzgerald in New York, Joshua Berman, said he does not think that Mr. Fitzgerald would bring a perjury charge based solely on a discrepancy in testimony between two individuals, such as Mr. Libby and Ms. Miller. Mr. Berman said such a charge is more likely to come from a stark conflict with the stories of mid-level White House aides who might have been aware of the alleged effort to discredit Mr. Wilson.

“Pat’s had lots and lots of witnesses in there right from the start,” said Mr. Berman, who is now a defense attorney in Washington. “My guess is Pat has proof and he’s got better proof than any of us know.”