Report: Holder signed warrant to seize Fox reporter's private email

Attorney General Eric Holder personally signed off on the search warrant that named Fox News reporter James Rosen as a potential criminal "co-conspirator," a law enforcement official told NBC News on Tuesday. 

That controversial warrant, revealed for the first time earlier this week, enabled federal law enforcement officials to seize Rosen's private emails as they sought to determine who leaked the journalist confidential intelligence about North Korea. 

The move, coupled with the Justice Department's recent seizure of the phone records of Associated Press reporters and editors, has led to tough questions for the White House about press freedoms.

The revelation that Holder personally signed off on the warrant also comes on the same day that President Obama announced the attorney general would lead a review into Justice Department guidelines on leak investigations.

At a national security speech, the president said he was "troubled by the possibility that leak investigations may chill the investigative journalism that holds government accountable," and had expressed that concern to Holder.

The attorney general, in turn, agreed to review Justice Department guidelines governing leak investigations and meet with a group of media organizations. Obama said that the Justice Department would present him with a report on media targeting by July 12.

"Journalists should not be at legal risk for doing their jobs," Obama said. "Our focus must be on those who break the law."

The Justice Department has charged State Department intelligence analyst Stephen Kim as the person responsible for leaking Rosen the information, which assessed how Pyongyang would respond to a United Nations resolution condemning the nation's nuclear program. Kim has denied the charges.

In his speech Thursday, Obama said Holder "shares my concern" that the investigations could have a chilling effect on investigative journalism. But he also stressed the need to thoroughly investigate national security leaks.

"We must keep information secret that protects our operations and our people in the field. To do so, we must enforce consequences for those who break the law and breach their commitment to protect classified information," Obama said.