The U.S. Justice department is launching an investigation into the disclosure of information that President George Bush ordered a secret eavesdropping program aimed at American citizens.
The New York Times reported two weeks ago that Bush ordered the super-secret National Security Agency to monitor phone calls and e-mails without first seeking court approval.
Critics say Bush broke the law when he authorized the actions.
For its part, the Whitehouse says that, besides being legal, the controversial spying has helped keep the U.S. safe from terrorists.
In a news conference just before Christmas Bush lashed out at whoever disclosed the leak. "It was a shameful act someone to disclose this very important program at the time of war," Bush said.
Now, in a familiar pattern for U.S. politics, after the leak of a government secret, the justice department is now investigating.
Officials are being tight-lipped about who requested the probe or how it will be conducted.
The Times reported earlier this month that, over the last three years, NSA has monitored the e-mails, telephone calls, and other communications of hundreds, and perhaps thousands, of people inside the U.S. without warrants.
The Times said it delayed publishing its story for a year after administration officials said the disclosure would harm national security.
Bush has defended the program, saying it was used only to intercept the international communications of people inside the United States who have been shown to have a "clear link" to al-Qaeda and related groups.
Justice Dept. opens probe on domestic spying leak.