The Transport Accident Investigation Commission has opened an inquiry into the cause of the fire on PeeJay V.
General manager for communications and investigation support Peter Northcote said two investigators were expected to arrive in Whakatane about mid-morning today to begin interviewing those involved, gathering information on the vessel and its operation, and to examine the vessel's remains 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 accidents in the future," he said in a statement.
White Island Tours managing directors Peter and Jenny Tait said they were upset the event had occurred; however, they had full praise for the efforts of their crew and staff, and were thankful to the emergency services that assisted with the rescue operation.
"We have planned and prepared for this scenario," Mr Tait said, adding they are proud of staff.
Mr Tait said the cause of the fire on board the vessel would be the subject of a full investigation and the company was working with the relevant authorities.
Meanwhile police have thanked local operators who assisted with the rescue and "undoubtedly saved the lives of those on board".