The Australian Maritime Safety Authority says it detected an emergency distress beacon signal early on Sunday about 648 kilometres north of the Antarctic mainland.
Two planes were unable to find the boat, believed to be a Tanzanian-flagged fishing support ship, but debris was seen in the location of the beacon signal.
If the reports are accurate and it is a Tanzanian-flagged vessel, it's likely to have been operating outside internationally accepted regulations.
The 25 member nations of the Commission for the Conservation of Antarctic Marine Living Resources agree a set of conservation standards for fishing in the region.
But vessels carrying flags from nations that aren't members, including Tanzania and Mongolia, which doesn't even have a coastline, are known to flout the regulations.
The Commission's Andrew Wright explains to Murray Silby that this can occur on a regular basis.