WASHINGTON — President Bush yesterday blocked an attempt by a House committee to obtain internal FBI documents from the CIA leak investigation, asserting that notes from interviews of Vice President Cheney and other White House officials are protected by executive privilege.

The move further escalates the conflict between the White House and the House Oversight and Government Reform Committee, which has issued a subpoena to Attorney General Michael Mukasey in an attempt to secure records related to FBI interviews in the leak investigation.

Mr. Cheney and other officials were interviewed during special prosecutor Patrick Fitzgerald’s effort to determine who disclosed the identity of a former CIA officer, Valerie Plame, to the press. The investigation eventually resulted in the conviction of Mr. Cheney’s former chief of staff, Lewis “Scooter” Libby, for perjury, obstruction of justice, and lying to the FBI. Rep. Henry Waxman, a Democrat of California and the panel’s chairman, said in a statement yesterday that Mr. Bush’s claim of executive privilege in the case is “ludicrous” and vowed to move ahead with a contempt citation against Mr. Mukasey.

“This unfounded assertion of executive privilege does not protect a principle; it protects a person,” Mr. Waxman said. “If the vice president did nothing wrong, what is there to hide?”

But in a letter to Mr. Bush released by Mr. Waxman’s committee, Mr. Mukasey argued that some of the reports sought by Mr. Waxman’s committee include summaries of conversations between Mr. Bush and his aides, which are covered by an executive legal privilege. In his letter, Mr. Mukasey asked Mr. Bush to invoke the privilege to prevent release of the documents.