Inpex has chosen $12bn plant site: Libs

State opposition leader Colin Barnett has accused Treasurer Eric Ripper of misleading the public over Japanese company Inpex Ltd's decision to build a $12 billion liquefied natural gas plant.

The company is currently deciding between Darwin and the Maret Islands in Western Australia as possible sites for the plant.

According to a report on ABC radio, Mr Barnett claims to have information that Inpex had told Mr Ripper's chief-of-staff nearly two weeks ago of its decision.

Mr Barnett said it was his understanding that Inpex had chosen to build the plant in Darwin.

However Mr Ripper has refuted those claims, saying Inpex had told him a week ago that it had not made its decision.

Yesterday Inpex announced it would start its second drill campaign in the Darwin Habour to assess whether the site is suitable for infrastructure, an offshore gas pipeline route and dredging.