The U.S. Justice Department is reopening an investigation into the Bush administration's domestic surveillance program, marking a major reversal in policy under new Attorney General Michael Mukasey.

The probe will focus on the conduct of Justice Department lawyers in approving the program, which allows the National Security Agency to eavesdrop on the e-mail and telephone conversations of Americans without getting prior approval from a special court. 

The Bush administration implemented the program after the September 11, 2001 terrorist attacks, and said it focused on intercepting international calls and e-mails of Americans and others in the U.S. with suspected terrorism links.

Attorney General Mukasey was formally sworn in Wednesday at a ceremonial event attended by President Bush.

The Justice Department's Office of Professional Responsibility began the probe in early 2006, but abandoned it after President Bush denied security clearances to investigators. 

Some information for this report was provided by AFP, AP and Reuters.