The U.S. Department of Justice is examining whether a decision by the White House television press pool to suspend coverage of President Donald Trump last month broke federal antitrust laws, a department spokesperson said Saturday.

Emily Covington, a Justice Department spokesperson, confirmed the investigation is underway.

She said the department’s Antitrust Division is investigating whether the news organizations involved violated any antitrust rules.

The investigation follows a move last month by the five broadcasters in the White House television pool to stop pool coverage of Trump after the administration restricted CNN, MS NOW and Politico’s access to the White House.