A Queensland MP who has spoken out against coal seam gas projects in the state holds shares in a company developing CSG sites south of the border.
But Opposition MP Howard Hobbs denies there's any conflict of interest.
It's been revealed the Liberal National Party Member for Warrego holds shares in Eastern Star Gas, which partly owns and operates the Narrabri CSG project in NSW's northwest.
Santos, which runs major CSG operations in central and eastern Queensland, has a 35 per cent stake in the project.
During parliamentary estimates hearings on Wednesday, Mining Minister Stirling Hinchliffe challenged Mr Hobbs about his ownership of the shares.
"Mr Hobbs wants to stop the CSG industry in Queensland where we have one of the strongest regulatory frameworks in the world," Mr Hinchliffe told the hearings.
"But he is also happy to personally profit from a company exploring and drilling for CSG in NSW where no safeguards for landholders exist."
Mr Hobbs denied any conflict.
"No of course not," he told ABC Radio.
"I've got no shares in companies that operate CSG or mining in my electorate here in Queensland.
"And at the end of the day, the (Queensland) government just have not been able to fulfil their obligations, they are not out there enforcing the rules."
He said the government had failed to respond to complaints he'd made about CSG infrastructure being too close to homes.