The Pike River Royal Commission has heard a delay in installing a gas monitoring system underground was a health and safety issue.
Doug White, general manager at the time of the disaster, is giving his third day of evidence to the inquiry in Greymouth on Thursday.
In evidence, Mr White told investigators he had pushed for the purchase of a tube bundle gas monitoring system and analysing machine costing $1 million.
Mr White told the commission on Thursday he had wanted the system in place before the first coalface was hydro-mined, but it was delayed by nine months by senior managers.
When asked if this was a health and safety issue, he agreed it was.
But when asked if he stood by his earlier statement that there was no reason to think there were any health and safety compliance problems at the mine, he chose not to answer for fear of incriminating himself.