The environmental issues surrounding "fracking" are about to go under the microscope, with the Parliamentary Commissioner for the Environment yesterday launching an official investigation.
Hydraulic fracturing - or fracking - is a method used to extract oil and natural gas locked in underground rocks, and has been banned in some countries because of environmental concerns.
The practice has been used in Taranaki for 20 years, and the Greens have called for a moratorium while further investigations into the environmental issues take place.
Commissioner Jan Wright has been looking at the issue, and yesterday announced she was stepping that up to a full investigation.
"The work that has been done by my office thus far shows a substantive case for an official investigation under the Environment Act," Dr Wright said.
"Over the next few months, my staff and I will conduct this investigation and produce a report to Parliament."
Dr Wright said she recognised that the issue was "hugely contentious", and she hoped to have the report completed this year.
Energy and Resources Minister Phil Heatley welcomed the inquiry, saying the results would enable the Government to move forward with confidence.
"There's no need for the Government to have an inquiry. We believe that this has been undertaken in New Zealand safely," the minister said.
"However, I think the parliamentary commissioner looking at it will be very good. It will answer some questions that have been unanswered, it will address claims that have been made."
Mr Heatley said the Green Party's environmental concerns were based on historical overseas research, and a moratorium was not necessary.
"The Greens want a moratorium on everything," he said.
"They want a moratorium on any sort of energy or electricity generation. Doesn't matter if it's wind, hydro, geothermal, they want to stop everything in New Zealand. We're just not prepared to do that."
Greens co-leader Russel Norman responded by saying his party wanted a moratorium on things that caused harm.
"Internationally, [fracking] has been found to have caused water pollution as well as air pollution," Dr Norman said.
"I think it's reasonable to take a precautionary approach before we contaminate our groundwater."