The number of people on the ferry which sank off the coast of Papua New Guinea yesterday morning may have exceeded the vessel's official capacity.
The Rabaul Queen sank between Kimbe on the island of New Britain, and the mainland city of Lae.
The acting chief executive of PNG's Maritime Safety Authority, Captain Nurur Rahman, says 238 survivors have so far been rescued but the search for more than 100 missing people is continuing.
He says no bodies have been sighted.
Captain Rahman says the ship's official limit was 310 people but about 350 are thought to have been on board.
"If the numbers were like this then they may have exceeded. The government is fully focused to continue with major investigation to find out the cause of this incident and to have legislation in place so these things don't happen in future."
Captain Rahman says while conditions were rough when the ship sank, they weren't unusual for the season.
A rescue official from PNG's maritime safety authority, Rony Naigu, says 100 people are feared trapped inside the ferry.