The blast shortly before 2pm (Noon AEDT) on Sunday was the fourth in the mine since an explosion on November 12 trapped 29 men in the mine.
Another blast on Wednesday dashed any hopes that the miners might be found alive.
There were 24 New Zealanders, two Australians, two Scots and a South African who died in the mine near Greymouth.
A third explosion tore through the mine on Friday afternoon.
There were no injuries from Sunday’s explosion and people working near the entrance to the mine were moved away from the area for their safety.
Superintendent Dave Cliff said the latest explosion demonstrated the volatility of the environment surrounding the mine.
“Our focus continues to be on the safety of those people working at the mine site and the recovery team.
“We are doing all we can to progress the recovery operation, however the explosion reinforces the risks involved in working in this environment and the requirement to put people’s safety first.”
NZPA was told that Sunday’s explosion blew away some of the infrastructure on top of the shaft.
Meanwhile, NZ Prime Minister John Key says the future of New Zealand’s entire underground mining industry is in doubt in the wake of the Greymouth disaster.
The industry, which has enjoyed a boom in recent years thanks to surging demand from Asia, could not continue if there was a risk of more tragedies such as this month’s Pike River pit explosion, Key told TVNZ.
Announcing he wanted a powerful Royal Commission to investigate the disaster, Key said: “In the end, the future of Pike River and actually underground coal mining in New Zealand rests on this.
“We can’t put people into mines that are dangerous.”
He said there were four underground mines in New Zealand and about 450 people were directly involved in the industry.
However, the wealth generated by the industry as Chinese and Indian steelmakers clamour for New Zealand’s high-quality coking coal means it is a major economic driver in small mining communities across the nation.
Key said he would ask parliament on Monday to set up a Royal Commission into the mine explosion at the remote South Island pit on November 19. Another blast eliminated any hopes for the miners’ survival, and a third followed.
He said the Royal Commission – the most powerful investigation available under New Zealand law – would be the first such inquiry called since a probe into an Air New Zealand crash in Antarctica in 1979 which killed more than 250.
Key said the Royal Commission, which will be headed by a judge and have the power to compel witnesses to testify, had “gravitas and does demonstrate the significance of this national tragedy”.
“There are serious questions that need to be answered,” he said, vowing the inquiry would leave “no stone unturned” to find the cause of the blast.