Cuadrilla Resources, the British shale gas explorer half-owned by ASX-listed AJ Lucas, has announced positive test results from its controversial fracking operation at Preston New Road, but warned it remains hamstrung from full production by heavy environmental restrictions.

The company said the first few months of hydraulic fracturing had revealed a "rich reservoir of recoverable high-quality natural gas". The gas had flowed from the shale at a peak rate of more than 200,000 standard cubic feet a day, and a stable rate of 100,000 standard cubic feet a day.