Investigators from Bougainville are still preparing to make their way to a remote PNG island where three bodies were found packed inside an illegal fishing boat's freezer.

The police assessment team has been delayed again, waiting in Bougainville's largest town, Buka, for a boat to travel to remote islands about 200 kilometres to the north.

The bodies were found packed among tuna in the freezer after the fishing boat ran aground at Paona Island, a 45-minute boat ride from Fead Island, which is 200 kilometres north of Bougainville.

The gruesome find was made on December 10 but the incident has only just been reported because of the remote location.

Bougainville disaster co-ordinator Frank Lacey, who is heading the investigation team, said the remaining crew members tried to destroy the boat before fleeing.

"Local reports coming from the area are that there are three dead bodies in the ship's fridge with some fish they have caught," he said.

"The occupants of the boat, when it ran aground, they tried to burn it.

"They tried to burn the ship. They do this all the time.

"But it did not get ablaze – it's only the top part of the ship that's been burnt."

The three bodies in the freezer are also yet to be identified but Mr Lacey said they appeared to be from Asia.

An earlier report suggesting the freezer was still working has now been dismissed.

The freezers are located on the second deck, out of the sun, and investigators hoped the frozen fish would keep the bodies from decomposing too quickly before they are identified.

"We've been giving a warnings to the locals not to get the fish from the fridge, which they normally do with other ships that run aground," Frank Lacey said.

Illegal tuna fishing is common in the area and the crew was believed to have fled to a "mothership", which was acting as a hub for smaller vessels.

One source told the ABC the call sign of the vessel had been tracked to a Chinese owner who had since been contacted.

The PNG National Maritime Safety Authority said the vessel was declared lost at sea in June, 2014.

The last known port of call was in Kiribati, hundreds of kilometres from Paona Island.

When the assessment team has completed its report, it will be handed to the country's National Maritime Safety Authority, which will lead the recovery of the bodies.

"We'll leave it to the NMSA to do the rest, because they could get the fish and dead people off and bury them somewhere," Mr Lacey said.