Work has partially resumed at Huntly East Mine after it was closed by inspectors on Wednesday night when elevated levels of potentially-lethal methane gas were detected.
Discussions are continuing between mine-owners Solid Energy and Labour Department inspectors regarding when the mine can become fully operational again.
Since lunchtime the miners have been allowed to prepare coal blocks for mining although they are still not allowed to mine it.
Barry Bragg, Solid Energy's chief operating officer, said the inspectors had requested more information about the mine's ventilation.
He said Solid Energy had been aware of the elevated level of gas, but had not seen it as a reason to halt work because they were ''managing it''.
Bragg was confident there was never any risk to workers, and that the mine was operating safely.
''The company deeply regrets any anxiety this incident and the resulting speculation has caused for its staff, their family and friends, and the local community,'' he said.
''The naturally occurring methane from the area in question, and all other potential hazards, were being managed in accordance with the mine's standard operating procedures for this situation.
''At no time did methane in this area exceed mining regulations standards.''
Bragg said he saw no reason why the notice banning the extraction of coal could not be lifted ''very soon'' but he was not more specific.
- © Fairfax NZ News