NSW announces new inquiry into Kathleen Folbigg’s conviction over her children’s deaths

The New South Wales attorney general has ordered a second public inquiry into the conviction of the woman dubbed Australia's worst female serial killer.

Mark Speakman, the attorney general of New South Wales, announced on Wednesday that the inquiry would consider whether there was a question or doubt over her conviction for the murder of three of her children and the manslaughter of a fourth.

A group of 90 scientists petitioned for her early release last year, arguing that there was no medical evidence that she smothered the children.

The petition came after scientists discovered that two of the daughters had a previously unknown genetic variant that could lead to sudden and unexpected infant death.

Her two dead sons could have stopped breathing while they slept.

Speakman believed there were enough questions to warrant a second public and that a pardon was not appropriate because the evidence had to be tested.

I can empathise with how members of the public feel about the number of chances that Ms Folbigg has had to clear her name, and how the justice system allows someone convicted of multiple homicides yet another chance.

The evidence clearly in my view reaches the necessary threshold for some kind of intervention; it certainly rises to the level of question or doubt.

I don't mean that I have formed a view on the guilt or innocence of Ms Folbigg, or on whether there is a reasonable doubt about her conviction. There was enough question or doubt to justify some form of intervention.

In 2003 she was sentenced to life in prison for the murders of her children and the manslaughter of her son. She won't be eligible for parole for another six years.

Speakman said it was appropriate for another hearing to consider the new evidence after a previous public inquiry upheld the conviction.

The fact that this evidence has come to light after the last inquiry is not the fault of Ms Folbigg or her lawyers, he said.

There were serious doubts about her conviction after the announcement.

Lawyer Rhanee Rego, who has worked as a solicitor, said there should be a cooperative approach to establishing the scope of the inquiry.

She said that for it to be fair and equitable, it must deal with the new genetic evidence and diary evidence.

Only a few of the 50,000 words written by Ms Folbigg were selected for the trial. The entries were focused on at the Inquiry.

We are confident that the overwhelming evidence will prove Kathleen's innocence.

The announcement points to the need for Australia to build a more scientifically sensitive and informed legal system, said Carola Vinuesa, an ANU professor.

It must be able to apply information to legal cases and understand advances in science. She said that this will help reduce the likelihood of others enduring a wrongful conviction.

Speakman said on Wednesday that he had spoken with the father of Kathleen's dead children, Craig, who told police about the suspicious diary entries which were key to her convictions.

Speakman said that Craig would have to sit through another inquiry.