The Department of Labour says it's confident it has the capability to investigate issues at the Huntly East Mine but will bring in outside experts if necessary.
The department's mines inspector met the mine's management in Huntly on Thursday to discuss an incident in mid-November when an explosive level of methane gas was recorded in the coal mine, prompting an evacuation.
National Services and Support General Manager Brett Murray says the inspector put to Solid Energy managers the questions the department wants answered about the systems at Huntly East.
Mr Murray says Solid Energy has taken immediate steps to deal with changes required by the improvement notice served on it after the incident.
He told Checkpoint that the inspector has not been underground to inspect the ventilation system and, with that area of the mine currently closed down, there was nothing to be gained.
Asked about allegations by miners that the ventilation systems were "old and inadequate", Mr Murray said Huntly East was audited in May by experienced Australian regulators who found no problem.
Mr Murray says the responsibility for mine safety rests firmly with the mine owners while it is the role of the department to ensure mine owners have the systems and processes in place to properly manage health and safety issues.
Solid Energy has its own investigation underway and Mr Murray says, if the department isn't happy with that, it will call in outside help.
Investigation can't be thorough - Labour MP
Earlier, Labour Party MP Andrew Little, who is a former general secretary of the union representing miners, said the government would not be able to thoroughly investigate the incident because it has been too slow to employ more mine inspectors.
The government announced in August that it would establish a High Hazards Unit with four inspectors to monitor mine safety, in response to the Pike River disaster.
But Mr Little says the department has been unable to attract staff for the unit and is incapable of investigating thoroughly.
"There is a weakness in the regulation and our oversight is too tardy," he says.
"We need more experienced people involved in that industry providing that oversight to lift the standard."
The department says two new mines inspectors have been appointed and recruitment of a Chief Inspector is underway.
Meanwhile, Waikato mayor Allan Sanson says the mine operator, state-owned Solid Energy, has a very good health and safety record.
Mr Sanson says he has confidence in the Department of Labour to investigate properly.
The mine is one of the biggest employers in Huntly and local people say it is very important to the community but must be safe.
Solid Energy says the danger from a gas build up has been vastly exaggerated.
