Washington ? The federal investigation into the leak of a CIA officer’s name expanded Thursday beyond the White House and the spy agency to other parts of the government with access to the officer’s classified identity.

The Justice Department sent “do not destroy” letters to the Defense and State departments requesting preservation of phone logs, e-mails and other documents that could become evidence in the inquiry, senior law enforcement officials said.

“We will cooperate fully,” said State Department spokeswoman Susan Pittman. Two Defense Department officials said they had been told earlier to expect such a letter

The goal for investigators is to cast as wide a net as possible for anyone who might have leaked the identity of Valerie Plame, a CIA operations officer who has served overseas. Plame is married to former Ambassador Joseph Wilson, who has accused the Bush administration of selective use of intelligence to exaggerate the threat from Iraq.

The Justice Department is conducting a criminal investigation into the leak of Plame’s identity, which first appeared in a July 14 column by syndicated columnist Robert Novak and later was reported by Newsday. The probe is focused on finding the leaker, not on prosecuting those who reported her name, officials say.

Justice Department policy is to consider seeking subpoenas of reporters only as a last resort, officials say.

“When it comes to the media, there are a lot of safeguards built into the system,” said FBI spokeswoman Susan Whitson.

Atty. Gen. John Ashcroft would have to approve any subpoenas for reporters’ notes or telephone records.

Bush spokesman Scott McClellan said Thursday that no White House staffers had been interviewed by the FBI and no subpoenas for records or documents had been received. McClellan promised to disclose any such subpoenas received by the White House, if the Justice Department did not object.

On Capitol Hill, the Democratic drumbeat continued for Ashcroft to appoint a special counsel to run the investigation. Democrats say someone outside the Justice Department could conduct a more thorough investigation because that person would not have political ties to the Bush administration.