WASHINGTON – Attorney General Eric Holder Jr. on Friday announced tighter controls over the ability of prosecutors to subpoena the phone and other records of journalists after criticism that the Justice Department’s aggressive pursuit of leak investigations was infringing on press freedom.

Under new guidelines, a reporter must be the target of a criminal investigation before Justice Department officials can obtain a search warrant for the journalist’s emails and other records.

News media organizations will also have to be notified if a reporter’s records are being subpoenaed, unless the attorney general decides it would harm a criminal investigation, according to a six-page report issued Friday and called “Review of News Media Policies.”

“The Department of Justice is firmly committed to ensuring our nation’s security, and protecting the American people, while at the same time safeguarding the freedom of the press,” said Holder in a statement. “These revised guidelines will help ensure the proper balance is struck.”

The guidelines, which will go into effect immediately, are the result of a backlash from the news media and press freedom organizations two months ago over a pair of newly disclosed leak investigations. In an unusually sweeping move, Justice officials obtained records from more than 20 phone lines assigned to the Associated Press and its journalists as part of a year-long investigation into the disclosure of classified information about a failed al-Qaida plot last year. The AP was not notified until 90 days later, which was permitted under existing guidelines.

Under the new guidelines, the Justice Department “will ensure notice in all but the most exceptional cases,” the report said. That action would allow news organizations to raise a legal challenge to the request.

If the attorney general decides such notice “would pose a clear and substantial threat to the integrity of the investigation, risk grave harm to national security, or present an imminent risk of death or serious bodily harm,” the department can delay notification for 45 days, according to the new guidelines.

At that point, the attorney general would again have to review his decision and may authorize a notification delay for up to an additional 45 days.

No further delays can be sought beyond the 90 day period. Under current guidelines, notification to a news organization could be put off indefinitely, Justice officials said.

In a second leak investigation into former State Department arms expert Stephen Jin-Woo Kim, Fox News reporter James Rosen was called a possible “co-conspirator” in a crime in order to obtain a search warrant for his records.