A former chief inspector of coal mines says the Pike River mine tragedy had its origins in the abolition of the dedicated mine inspectorate at end of the 1990s.
A Royal Commission is being held in Greymouth into the deaths of 29 men killed in a series of explosions at the West Coast mine in November last year.
Robin Hughes told commission on Wednesday that changing the inspectorate from a proactive to reactive system was like having an ambulance at the bottom of the cliff.
Mr Hughes says the government of the day ignored strong objections from mine inspectors to the ending of the mines inspectorate and the transfer of all inspectors to the Department of Labour.
He says proactive inspections of mines were discouraged.
Mr Hughes says his private view is that the return of dedicated mine check inspectors would be beneficial for safe operations.
'Complex' geology at mine
A coal geologist also gave evidence on Wednesday and said the Pike River Coal company had not done enough bore hole testing to accurately define the complex geology of the mine.
Jane Newman told the inquiry it was difficult to convey her concerns about the geology of the mine because the company seemed too busy and preoccupied.
Dr Newman felt Pike River Coal did not have a sufficient understanding of the mine's complex geological structure.
She said the stratigraphy of the coal seam being mined by Pike River Coal was difficult to understand and believed the company had not done enough drill hole testing to accurately define it.
She told the hearing it was hypothetical, but possible, that trapped gas could be released because the structure was not properly understood.
"There's debate about how hazardous that would be, but there is the possibility of gas trapped in this undrained area under this false floor potentially being released in an outburst."
Dr Newman said she thought some of the people carrying out geological analysis for the Pike River company were from overseas and did not understand the particular geological issues of the West Coast.
She also thought the company may have been hindered from doing more vertical drill testing because of having to go through the process of getting consent from the Department of Conservation.
Dr Newman said it was difficult for Pike's geology staff to get the attention of management, and day-to-day problems of the company caused a busy, preoccupied feeling in the organisation.
She told commissioners that her husband Nigel, also a geologist, often worked for Pike River. However, in July or August last year, she had asked him not to go there for a job. She said her concerns were not specific but she was not happy with him being in the mine.