Labour Minister Simon Bridges says the police decision not to lay any individual criminal charges against anyone for the deaths at Pike River Mine was clear cut and understandable.
The police announced on Wednesday no criminal charges will be laid against company managers in connection with the 2010 disaster, because of insufficient evidence.
Mr Bridges says the families' disappointment with the decision is understandable but so is the police decision.
He says when deciding to prosecute, the police have to look at whether there is sufficient evidence and public interest and those requirements couldn't be satisfied.
"When deciding whether to prosecute, and we know here that they have put huge resources - 34 million pages of documents I think it was - into this they have to decide on the basis of two criteria - evidential sufficiency and public interest - and in both of those it sounds like after an agonising decision-making process they couldn't be satisfied."
Mr Bridges says the Ministry of Business, Innovation and Employment has laid charges against two companies and an individual over the deaths.