An American journalism professor is suing the U.S. government over a Pentagon policy that bans the release of pictures of coffins containing U.S. soldiers killed overseas.

University of Delaware professor Ralph Begleiter, a former CNN correspondent, filed the lawsuit under the Freedom of Information Act.

The suit seeks to force the Pentagon to release photographs and videos of flag-drapped coffins arriving at Dover Air Force Base from the wars in Afghanistan and Iraq.

The Pentagon has refused to allow publication of the images, saying it is following a 1991 order intended to protect the privacy of dead soldiers and their families.

The lawsuit, and other critics, argue the Pentagon policy is a way of hiding the human cost of war from the American public.