Kathleen Folbigg is serving 30 years in prison for murdering her four infant children.

Her first born son, Caleb, lived 19 days. Her second baby, Patrick, lived eight months. Her third baby, daughter Sarah, lived 10 months. And number four, baby Laura, lived to be 19 months of age.

But her lawyers are now arguing that there was no evidence that her children died of anything but natural causes. They have petitioned the Governor saying, that there are “no signs in or on the bodies to positively suggest that the Folbigg children were smothered or killed by any means.”

Parallels are being drawn with Lindy Chamberlain, with Folbigg’s supporters saying that she was convicted because she didn’t behave like a “normal” mother.

Kathleen Folbigg.

When Caleb, Patrick and Sarah died, their deaths were initially labelled ‘cot-death.’ It was the death of 19-month old Laura, the fourth infant death in one family, which prompted police investigation.

The NSW Supreme Court convicted Folbigg of the manslaughter of  Caleb, and the murders of Patrick, Sarah and Laura. Folbigg was also convicted of grievous bodily harm after an alleged smothering attack left Patrick, who was four-months-old at the time, blind.

She was sentenced to 40 years, with a 30 years non-parole period.

Folbigg has maintained her innocence since her conviction in 2003, and after launching an appeal in 2005, had her sentence reduced to 30 years’ imprisonment with a non-parole period of 25 years.

Folbigg claims that all of her children died of natural causes – and there is some expert evidence that backs up her claims.

In 2013, 60 Minutes interviewed legal academic Dr Emma Cunliffe about the trial, and in particular, the medical examiners testimony. Here is what she had to say:

But now the ABC reports, that a petition has been made to NSW Governor General David Hurley. In that petition,  Stephen Cordner, Professor of Forensic Pathology at Monash University states, “If the convictions in this case are to stand, I want to clearly state there is no pathological or medical basis for concluding homicide.”

Laura (left) and Patrick (right) Folbigg.

“It seems not to have been explicitly stated in the trial, but there is no forensic pathology evidence, no signs in or on the bodies to positively suggest that the Folbigg children were smothered,” Cordner said. “Or killed by any means.”

As ABC reports, much of the case against Folbigg was based on notes she had written in her personal diary:

Perhaps most significantly, Folbigg wrote,”Obviously I’m my father’s daughter.” Kathleen Folbigg’s mother was murdered by her father, Thomas Britton, when she was a child.

Sarah (left) and Caleb (right) Folbigg.

At the time, Folbigg’s legal team insisted that while the notes suggested she was under stress, they were emotionally consistent with the thoughts and feelings of a mother who had lost multiple children. It would be natural for a mother in this horrific situation to blame herself.

Newcastle Legal Centre Director, Shaun McCarthy, along with a team of barristers and law students have been preparing a petition for judicial review since 2014.

Folbigg’s sister Lee Brown (Image: Australian Story).

But ABC reports that Folbigg’s foster sister Lee Brown wants her to remain in prison. “She was found guilty and she’s had two to three tries at trying to get out and have a new trial and it was knocked back,” she said.

“I think it’s wrong….Somebody has got to speak up for the kids”.