Brittany Groth today called a report by the Herald Sun “a disgraceful smear campaign” after it questioned whether she was underage when she commenced a relationship with Mr Groth in 2011.

“The Herald Sun‘s decision to speculate salaciously about my personal life from 14 years ago, when I was a teenager, is not journalism,” she said.

It comes as news emerged that the professional tennis player turned politician has threatened legal action against Labor MP Mary-Anne Thomas following her commentary on the matter.

Earlier this week, Thomas responded to media questions about the purported scandal.

“If you can’t govern yourselves, you can’t govern the state,” Thomas said.

“But if you’re asking me if it’s appropriate for a person in a position of influence or authority … like a teacher or a coach to be dating a teenager, the answer is no.

“And I think most parents would stand with me.”

Opposition Leader Brad Battin declined to comment on the matter.

“Any matters now for Sam Groth are a private matter. I just won’t be commenting further,” he said.

Premier Jacinta Allan said families should be “very much off limits” in the public sphere.

The Herald Sun has been contacted for comment.