The U.S. government is trying to stop a planned expedition to recover items of historical interest from the sunken Titanic, citing a federal law and an international agreement that treat the shipwreck as a hallowed gravesite.

The expedition is being organized by RMS Titanic Inc., the Georgia-based firm that owns the salvage rights to the world’s most famous shipwreck. The company exhibits artifacts that have been recovered from the wreck site at the bottom of the North Atlantic, from silverware to a piece of the Titanic’s hull.

The government’s challenge comes more than two months after the Titan submersible imploded near the sunken ocean liner, killing five people. But this legal fight has nothing to do with the June tragedy, which involved a different company and an unconventionally designed vessel.