The yearlong, $48 million search for a missing Malaysia Airlines jet has at last uncovered wreckage, albeit likely not that of the missing plane.

The Australian-led search team on Wednesday released images appearing to show a previously unrecorded shipwreck 3,900 meters below the surface of the southern Indian Ocean.

It said one of four ships involved in the hunt for wreckage from Flight MH370 detected a cluster of sonar contacts in the southern part of the search area and directed a companion vessel to send down a remotely controlled submersible for a closer look.