Importing liquefied natural gas could potentially require one billion dollars in capital investment

Major energy companies, Clarus , Contact Energy, Genesis Energy, Meridian Energy, and Mercury have commissioned two studies, looking into the option.

Data out last month, shows New Zealand's domestic gas supply is reducing faster and sooner than previously forecast.

Clarus chief executive Paul Goodeve says it would be expensive.

But he says the group believes the value to the economy, by having certainty of supply, may make it worth while.