A former miner who worked at the Huntly mine now at the centre of two separate investigations has slammed its safety procedures.
Robert Kaweroa, 76, worked at the Huntly coalface for more than 40 years and also worked as a mine safety check inspector.
He was concerned that workers in the Huntly East mine were exposed to a "very, very dangerous situation" when methane levels rose as high as 5 per cent on November 11.
Solid Energy, which owns the mine, said the "higher-than-normal" gas levels were due to a geological fault.
Mr Kaweroa said the workers should have been evacuated sooner: "Five per cent is very high, it's a very, very dangerous situation.
"In my time if it was 2 per cent in the section you were working the miners had to go out immediately, that was a worry."
Mr Kaweroa, who retired from the mines about 12 years ago, said he always felt safe in the job because of the constant monitoring.
"These days there are no safety inspectors, it's one of the bigissues."
Yesterday the Department of Labour's high hazards unit general manager, Brett Murray, met Solid Energy as part of its investigation into the mine's spike in methane levels.
Mr Murray said Solid Energy's systems at the mine appeared to have adequately identified and managed the response, but the department was investigating the circumstances that led to the spike.
He said Solid Energy had taken immediate steps to deal with the changes required by an improvement notice the department had issued last week.
"This is appropriate and reflects the seriousness of the event. The company has also put a health and safety representative on its investigation team."
Mr Murray said the unit would review Solid Energy's outcomes from its investigation as part of its response to the incident.
The unit has been criticised by newly elected list MP and former head of the EPMU Andrew Little, who said there were difficulties attracting inspectors to join the new high hazards unit, which the Government announced in August in response to the Pike River disaster.
The unit was to employ four mines inspectors but the department still had only one inspector.
"As I understand it they are having difficulty attracting people and that's why we don't have a high hazards unit in place. It just shows once again that we're just not taking this stuff seriously enough," Mr Little told Radio New Zealand.
"Until they get their high hazards unit in place with properly qualified, experienced and properly paid mines inspectors, then I don't think we can expect that this incident, and any other incident, is going to be properly and thoroughly investigated."
Mr Little said there was no effective oversight of underground mining, which was "a very dangerous situation to be in".
Solid Energy did not respond to Herald questions in time for this edition but said it was also investigating non-compliant actions of two experienced miners on November 15.
- additional reporting APNZ