At least 300 cubic metres of soil have reportedly been contaminated at a Taranaki gas field, and fracking, a controversial drilling method, may be involved.

Six wells at the Kapuni gas field near New Plymouth are contaminated, and soil from one site had to be transported to a waste treatment plant to be re-stabilised, 3 News reported.

Three hundred cubic metres of soil was removed from the site in total, and there are five sites yet to be cleaned.

The Taranaki Regional Council confirmed to 3 News that fracking, the procedure of injecting fluid and chemicals into rock to force it to open, may be involved.