Mr Hunter argued the corruption watchdog's decision was not a lawful one and by extension, neither were the charges against her.

But CCC barrister James Renwick SC said it was merely a procedural matter.

"If the CCC is going to issue a notice to appear a decision needs to be made about whether it's a closed or open hearing," he said.

"That's all we're saying happened here."

Mr Renwick claimed the CCC chairman wasn't required to review all material collated during an investigation before he decided to question someone, but even if he were, the most recent information wouldn't have made a difference.