The Morrison government is caught up in another inquiry into one of its own senior figures after Resources Minister Matt Canavan revealed a potential conflict of interest over a $20 million loan.

Senator Canavan announced on Monday night he had not declared his link to the North Queensland Cowboys football club at the time it gained the loan from the Northern Australia Infrastructure Facility.

Nationals Senator Matt Canavan has revealed he approved a $20 million loan to a rugby league club he held a membership with. Credit:Trevor Collens

"I don't have any control or influence over the football club itself but at the same time it's an interest that I should have declared and I have not," he said.

"I've sought advice from the Prime Minister's office about it. I don't believe there's a breach of ministerial standards.