Queensland Premier Campbell Newman says his side of politics isn’t responsible for leaking private information about a Labor candidate.

Queensland Premier Campbell Newman says his side of politics did not leak private information about Labor’s candidate in the upcoming Stafford by-election.

It’s been revealed Labor candidate, surgeon Anthony Lynham, owes money to Queensland Health as a result of overpayments made during the bungled rollout of a new health payroll system several years ago.

Labor has demanded an investigation into how his personal payroll information came to be in the public domain ahead of the July 19 poll.

The party says Dr Lynham was advised some time ago that he could resolve the overpayments issue when he left Queensland Health.

“How did someone access Dr Anthony Lynham’s personnel file?” Opposition Leader Annastacia Palaszczuk said.

“If Campbell Newman does not launch an immediate investigation I will be asking the tough questions at estimates (hearings).”

But Mr Newman said the LNP had nothing to do with leaking the information, which was published in The Courier-Mail on Thursday.

“I’m very confident that’s not the case. I can simply assure people of that,” he said.

He said there were mechanisms available to Dr Lynham if he wanted to lodge a complaint.