In a four-page opinion, Magistrate Judge John Facciola said the White House is ignoring the court's instructions to search a full range of locations for all electronic messages that may be missing.

The Executive Office of the President, the magistrate said, is limiting its search to offices subject to the requirements of the Federal Records Act. It also needs to examine different offices covered by a different law, the Presidential Records Act, Facciola said.

"The importance of preserving the e-mails cannot be exaggerated," Facciola wrote.

The Bush White House has represented to the court that no office under the federal records law received records created by any office covered by the separate law. But the magistrate said there is no factual record to support that assertion.

Lawsuits against the White House over its problem-plagued e-mail system were filed under the Federal Records Act.

Facciola said the case must be dealt with in "true emergency conditions" because the Bush administration ends Tuesday.

"The records at issue are not paper records that can be stored, but electronically stored information that can be deleted with a keystroke," Facciola wrote. "Additionally, I have no way of knowing what happens to computers and to hard drives in them when one administration replaces another."

Facciola's opinion raises questions about the completeness of the Bush administration e-mail search. The Justice Department says the government has finished a search that entailed spending more than $10 million to locate 14 million e-mails thought to be missing in 2005, when White House technical experts discovered a problem with the system.

But in a court filing following Facciola's ruling, the administration revealed it has made almost no use of disaster recovery backup tapes. They are the one source that would make it possible to determine for certain whether any e-mails are missing e-mails and if so, how many.

Facciola's opinion is the third time in two days that a federal court has taken the Bush White House to task for its handling of missing e-mail, a problem first publicly disclosed three years ago by the federal prosecutor investigating the administration's leaking of Valerie Plame's CIA identity.