Further services are planned this week for the victims of Wednesday's crash.
Rescuers recovered the bodies of 30 men, women and children from the ocean, while 42 people survived.
Australian Federal Police Superintendent Gavan Ryan said about 15 bodies had been identified so far by surviving family members and friends who were either on the boat or were already in the island's detention centre.
Officials say the boat could have held up to 100 Iraqi, Iranian and Kurdish passengers.
Mr Ryan said he believed more bodies could be in underwater caves near the crash site. "We are hoping by the end of tomorrow to have a definite answer of how many people are missing," he said.
The tragedy has once again put the spotlight on the three-year-old Labour government's struggle to come up with an effective refugee policy. Critics on both sides say the current approach encourages asylum seekers to undertake perilous sea journeys.
Opposition leader Tony Abbott urged the government to return to tougher refugee laws that he said would keep the boats from coming to Australia."It is important that we put policies in place as quickly as humanly possible that do offer the prospect of stopping the boats."
His coalition wants a return to temporary visas for those approved as refugees, offshore processing of refugee applications and turning boats around in the ocean when it is safe to do so.