Police Deputy Commissioner John Tims said the terms of reference for the investigation will be determined in coming days, The New Zealand Herald reported
The announcement comes as attempts to recover the eight people on the island who are missing, presumed dead and likely to be covered in ash.
Tims said a boat was sent to the island on Tuesday to try and launch a drone but it was too windy. A second attempt will be made later in the day if conditions allow.
The drone will capture the gasses which will be analysed and then the safety of the island will be seen from that.
Tims answered a question about a picture of the island that had markings about where bodies could potentially be.
There were six markings currently, likely to be six bodies, but two more people are missing.
Those feared dead are from New Zealand, Australia, Britain, the US, China and Malaysia.
The bodies of the dead are "certainly" covered in ash, he added.
Of the 31 injured, 25 are in four regional burns units around the country. The six others will be transferred to burns units as soon as possible, according to health authorities.
Meanwhile, experts have warned that there was a 50 per cent chance of another eruption within 24 hours, The New Zealand Herald reported.
A total of 47 people were on the island when it erupted on Monday afternoon, sending an ash plume 12,000ft into the air.
They were aged between 13 and 72 and most and 38 were tourists from the cruise ship Ovation of the Seas, which was docked in Tauranga.
Many of the White Island victims mights have been knocked out almost instantly by toxic gases, said investigators.
Speaking to the media on Tuesday morning, Prime Minister Jacinda Ardern said that "no signs of life have been seen at any point" after helicopters and aircraft took a number of aerial reconnaissance flights over the island since the eruption.
"It is now clear that there were two groups on the island those who were able to be evacuated and those who were close to the eruption," she added.
( With inputs from IANS )