The case surrounding Valerie Plame -- and the possible involvement of administration officials in the leaking of her name and identity -- does not appear to be going away. First, Bloomberg carries a story that could portend poorly for some involved in the investigation.

Two top White House aides have given accounts to a special prosecutor about how reporters first told them the identity of a CIA agent that are at odds with what the reporters have said, according to people familiar with the case.

Lewis ``Scooter'' Libby, Vice President Dick Cheney's chief of staff, told special prosecutor Patrick Fitzgerald that he first learned from NBC News reporter Tim Russert of the identity of Central Intelligence Agency operative Valerie Plame, the wife of former ambassador and Bush administration critic Joseph Wilson, one person said. Russert has testified before a federal grand jury that he didn't tell Libby of Plame's identity, the person said.

White House Deputy Chief of Staff Karl Rove told Fitzgerald that he first learned the identity of the CIA agent from syndicated columnist Robert Novak, according a person familiar with the matter. Novak, who was first to report Plame's name and connection to Wilson, has given a somewhat different version to the special prosecutor, the person said.

These discrepancies may be important because Fitzgerald is investigating whether Libby, Rove or other administration officials made false statements during the course of the investigation. The Plame case has its genesis in whether any administration officials violated a 1982 law making it illegal to knowingly reveal the name of a covert intelligence agent.

The New York Times' David Johnston adds another wrinkle to the story.

At the same time in July 2003 that a C.I.A. operative's identity was exposed, two key White House officials who talked to journalists about the officer were also working closely together on a related underlying issue: whether President Bush was correct in suggesting earlier that year that Iraq had been trying to acquire nuclear materials from Africa.

The two issues had become inextricably linked because Joseph C. Wilson IV, the husband of the unmasked C.I.A. officer, had questioned Mr. Bush's assertion, prompting a damage-control effort by the White House that included challenging Mr. Wilson's standing and his credentials. A federal grand jury investigation is under way by a special counsel to determine whether someone illegally leaked the officer's identity and possibly into whether perjury or obstruction of justice occurred during the inquiry.

People who have been briefed on the case said that the White House officials, Karl Rove and I. Lewis Libby Jr., were helping to prepare what became the administration's primary response to criticism that a flawed phrase about the nuclear materials in Africa had been included in Mr. Bush's State of the Union address six months earlier.

They had exchanged e-mail correspondence and drafts of a proposed statement by George Tenet, then the director of central intelligence, to explain how the disputed wording had gotten into the address. Mr. Rove, the president's political strategist, and Mr. Libby, the chief of staff for Vice President Dick Cheney, coordinated their efforts with Stephen Hadley, then the deputy national security adviser, who was in turn consulting with Mr. Tenet.

At the same time, they were grappling with the fallout from an Op-Ed article on July 6, 2003, in The New York Times by Mr. Wilson, a former diplomat, in which he criticized the way the administration had used intelligence to support the claim in Mr. Bush's speech.

The work done by Mr. Rove and Mr. Libby on the Tenet statement, during this intense period, had not been previously disclosed. People who have been briefed on the case discussed the critical time period and the events surrounding it to demonstrate that Mr. Rove and Mr. Libby were not involved in an orchestrated scheme to discredit Mr. Wilson or disclose his the undercover status of his wife, Valerie Wilson, but were intent on clarifying the use of intelligence in the president's address. Those people who have been briefed requested anonymity because prosecutors have asked them not to discuss matters under investigation.