New Zealand Department of Labour inspector Michael Firmin, who inspected the mine a number of times between 2005 and 2008, was the only witness to give evidence on the first day of phase three of the inquiry, which was described as the “largest phase of the inquiry” by the commission.

Under a gruelling cross-examination by lawyer James Wilding, Firmin said there was no formal auditing of the Pike River health and safety management systems during his time as an inspector.

“I did inspections underground and at times you may identify a problem with the health and safety management system but no, I certainly didn’t do any formal auditing,” Firmin said.

“Because of the limited amount of time we had on site, I felt that there was a need to go underground, that is in some ways the best check to see whether the systems are working properly, rather than perhaps do the audit outside,” he said.

When asked if the department had provided Firmin with training in auditing a mine system he revealed it had not, while a discussion prior to the disaster about the department getting an audit tool or system had been dismissed.

“I think we had brought that up at a mining steering group meeting that we would like to do some audits, but nothing ever came of it,” Firmin said.

During questioning Firmin revealed he didn’t know if Pike River had a formal system for identifying hazards and he had never been involved in an underground coal mining incident prior to Pike River.

The DOL came under a set of fresh scrutiny following Firmin’s evidence, after he claimed the department had never given him any training in assessing complex issues such as methane drainage and ventilations systems.

He also said the DOL never oversaw the inspectors, and the department had never reviewed his assessment processes at the mine, adding they had “quite a lot of flexibility in a sense of the approach that we would take”

Firmin confirmed that the department had never considered engaging expert advice in relation to any aspect of the Pike River mine prior to the tragedy.

Wilding went on to question Firmin about whether or not his inspections at Pike River complied with the rules set out in the Health and Safety in Employment Act.

“I take it, fair to say at this stage that the inspections that you conducted at Pike River and the enquiries you made weren't sufficient for you to be able to form a view as to whether or not Pike River and its contractors were complying with the Health and Safety in Employment Act and regulations?,” Wilding said.

“Well, true, we weren't … when I look back once every three months was obviously not enough and we should have been auditing,” Firmin responded.

During questioning time, Firmin was asked if the mine’s ventilation shaft was an appropriate means of egress.

While he said it met legal requirements, he admitted an additional tunnel would have been a “far better proposal.”

Earlier in the day commission lawyer Simon Mount said the use of trial hydromining at Pike River, two months before the disaster, would be thoroughly investigated during Phase three.

“On the information available to the Commission, it appears that hydromining was an activity at Pike that carried with it particular risks and particular hazards that warrant attention,” Mount said.

“It’s too soon to say whether hydromining did or did not contribute to the first explosion on the 19th of November 2010, but clearly it is an area that warrants examination.”

Phase three of the inquiry is scheduled to be broken into three blocks of two weeks, running through November, December and February.

Queensland Mining Inspectorate employee and former DOL safety inspector Kevin Poynter is due to give evidence today.