The Green Party says there have been decades of negligence relating to the use of hydraulic fracturing in New Zealand.
The Greens say requests under the Official Information Act showed councils and Government agencies have no record of exactly what chemicals have been used in the process, known as fracking, from 1989 until mid-2011.
The party says that means companies, particularly in Taranaki, could have been using potentially dangerous and toxic chemicals with little government oversight.
The Greens' energy spokesperson Gareth Hughes says fracking is under-regulated and a moratorium should be introduced until it can be proven to be safe.
Fracking involves injecting water, sand and chemicals into oil or gas reservoirs to crack open rock and boost petroleum flow.
Fracking did not need resource consent between 1989 and mid-2011 and companies were not required to submit records of the chemicals they used.
Taranaki Regional Council says fracking in the region has an exemplary track record and any unknown chemicals would have been contained.
