Fears a gas supply shortage on Australia's east coast is being caused by exports to Japan is a "peak conspiracy theory", according to the resources minister.
Japan has long-term contracts with gas suppliers in the Northern Territory and Western Australia with few exports being provided by suppliers to the eastern seaboard.
While the gas is for Japan's domestic use, it on-sells surplus requirements to other south-east Asian countries.
Resources Minister Madeleine King told ABC's RN program on Tuesday it was "manifestly incorrect" that the gas being on-sold was reducing supply on the eastern seaboard.
"It seems bizarre to me that people might think the Japanese government and these Japanese companies have contrived to spend all this money developing these projects over decades, not with a primary aim of underwriting their own energy security, but for some kind of notion that they might seek to profiteer off gas and on‑sell it. That is sort of peak conspiracy theory in my opinion," she said.
Ms King said Japan's gas needs fluctuated depending on weather and demand and if it was not on-sold then it would be dispelled into the air as methane, polluting the environment.
"The gas that goes to Japan is not really available to the domestic market in Australia, simply because it's not connected to the places from which it is extracted. It's as simple as that," she said.
Ms King said the lack of pipelines connecting Australia's west and north to the eastern seaboard meant it was not easy to move gas across the country.
She also said there was sufficient supply in the system to satisfy the eastern seaboard's gas needs this winter.
"At the moment there is a bit of a pipeline constraint, I won't deny that," Ms King said.
