Investigations are under way to discover what went wrong at the Pike River Coal mine.
It is still unclear when it will be safe enough to retrieve the bodies of the 29 men, after a second explosion at 2.37pm on Wednesday.
Prime Minister John Key has confirmed that a commission of inquiry will be approved by Cabinet on Monday.
The chief coroner, Judge Neil MacLean, has launched an inquiry, which may or may not result in an inquest into the deaths.
Investigations have also been confirmed by police and the Labour Department, though it is not clear what form they may take.
Pike River Coal has confirmed it will conduct its own examination of the disaster.
Energy Minister Gerry Brownlee says a range of inquiries will begin immediately because everyone will want to know what happened. Mr Brownlee says the Department of Labour has not expressed concerns about the way the mine was run or methane levels in the mine.
Mr Key says the inquiries will have implications for the rest of the mining industry. He says Solid Energy runs a mine near the Pike River site at Spring Creek which has to deal with similar methane leakages.
New Zealand has been involved in underground mining for a long time, he says, and it is vital the inquiries find out what went wrong and what it means for the rest of the industry.