Prime Minister John Key has defended mining safety standards and he is not alone.
"One of the experts we saw yesterday, in the United States, said that New Zealand mine safety standards are world class," said Key.
But two years ago the Labour government got the Department of Labour to review mining safety standards.
It found that safety rules were fundamentally sound but it did identify some concerns and suggested stricter monitoring and more inspections.
"Some of that was picked up but I think the major concerns were in relation to small mines," said Labour Minister Kate Wilkinson.
"We don't have any small mines so in relation to Pike River which is a tragedy, it wasn't that relevant," said Wilkinson.
But ONE News has obtained the submission that the Pike River Coal company made to that review. Advertisement
It called for an increase in the coverage and the number of mine inspectors through realistic resourcing of the Department of Labour.
The submission says the number of qualified mine inspectors has dramatically dropped over the past decade.
Wilkinson said New Zealand has two mine inspectors plus an expert.
Asked if that is enough, she said: "Well I have got no advice to suggest that it is inappropriate."
But when asked to name the biggest safety concerns in the industry the Pike River Coal company said: "Levels of competence and experience of workers and contractors working underground is of concern. The inspectorate is seriously under-manned and under-resourced."
Andrew Little of the Engineers' union, the EPMU, said that has been known in the mining industry for some time "and I think all mining companies have shown concern about that".
The government says it is too early to fully examine all this.
"We've got a long way to go. At the moment we've got grieving families there, they want their men back," said Wilkinson.
ONE News Political Editor Guyon Espiner says whether that happens or not, serious questions will be asked about whether mining safety standards can be improved.