The requested vessel with name AUSTRAL LEADER and MMSI:0 and IMO:6725121 is temporary not in our database.
Perhaps you mean one of the following ships:

Vessel name IMO MMSI In range Destination Last report
AUSTRAL LEADER 11 7382770 503556000 ALANG Mar 24, 2016 16:25 UTC

Also, you may try to find the vessel in our comprehensive Vessels Database or track this ship on the map.