President Barack Obama's administration defended its decision not to release photos of Osama bin Laden's dead body on Thursday, warning that doing so would risk "grave damage" to national security.
The al-Qaeda leader was slain in May 2011 in a raid on his Pakistani compound by US commandos, who took pictures of their target in order to confirm the success of their mission.
Media outlets around the world sought access to the 52 photos taken during the operation, but the Obama administration has resisted, warning that the images could excite an angry, even violent reaction against Americans.
In April last year, a court threw out the media's suit, accepting the position of the CIA that their publication could harm national security.
A conservative watchdog, Judicial Watch, appealed the decision, leading to Thursday's hearing, at which the Department of Justice warned of possible "grave damage to the national security" if the pictures were published.
It was not immediately known when the federal appeals court will issue its ruling.