A spokesman for the commission said they would also look to examine the remains of the vessel, if possible.
"The purpose of the commission's inquiry will be to identify the circumstances and causes of the accident, with a view to helping prevent similar accident in the future," he said.
The Coastguard said police were now the leading agency in the matter. But a police spokeswoman said the owners of the vessel were the main people handling inquiries.
A source close to the operation said bad weather in the area would possibly hamper any efforts to salvage the boat, which has since sunk.
Officials are set to decide whether it may be a navigational risk. If not, a decision to leave it there may be the best option, they said.
Police last night praised local boaties who answered the call for help in rescuing passengers and crew on the burning vessel. "[We] would like to thank the response of local operators who ... undoubtedly saved the lives of those on board."
A total of 60 people - 53 passengers and seven crew members - were on the tour boat when it caught fire shortly before 3.45pm.
A general call asked any boats in the area to assist in the rescue. There was an immediate response, with four large vessels and a Coastguard boat arriving at the scene quickly.
The Rescue Co-ordination Centre got a mayday call about 4pm, saying the vessel was being abandoned.
White Island Tours managing directors Peter and Jenny Tait praised staff and emergency services for their quick actions.
"We're extremely upset this has occurred and we are trying to come to terms with it. But we're extremely proud of our crew and staff for their efforts - and thankful to the emergency responders who assisted."
They said they had planned and prepared for such a scenario and would be helping passengers who lost personal items on the boat.
Last night four people who had been on the vessel were in a stable condition in Whakatane Hospital.
A Bay of Plenty District Health Board spokeswoman confirmed it was treating four patients - up from the initial two people, understood to be a passenger and a crew member, police said had been taken to hospital.
Those in hospital are a 36-year-old man from Ohope, a woman from New Plymouth, 35, a woman from Ohope, 23, and a 47-year-old woman from South Australia.