The final report from the Inquiry into the Convictions of Kathleen Folbigg "shows unequivocally a system that failed Ms Folbigg", a Greens MP has said.
An appeals court will be asked to consider overturning Folbigg's convictions for killing her four children in the Hunter region after the inquiry found there was reasonable doubt of her guilt.
Folbigg received an unconditional pardon in June and was released from jail after a NSW inquiry heard new scientific evidence indicated she might not be responsible for her childrens' deaths.
In his final report released on Wednesday, inquiry commissioner Tom Bathurst found there was an "identifiable cause" for three of the deaths and Folbigg's relationship with her children did not support the case that she killed them.
The former NSW chief justice added that the mother's diary entries - controversially used during her trial to help secure her conviction - did not contain reliable admissions of guilt.
Greens MP and the party's spokesperson for justice, Sue Higginson, said the system failed Ms Folbigg "every step of the way".
"The report shows unequivocally a system that failed Ms Folbigg," Ms Higginson said.
"She spent 20 years in prison, when she consistently maintained her innocence and there was always actual doubt about her guilt.
"The post criminal conviction review system in NSW is antiquated, loaded with discretion and in desperate need of reform and Ms Folbigg's case is testament to that.
"It is unacceptable that NSW doesn't have a modern, accessible and fair system of post conviction review and those who claim they are wrongly convicted must beg the Attorney General to pardon them."
The 55-year-old's lawyer welcomed the report findings as "another significant positive milestone in Kathleen's 24-year journey to clear her name".
Kathleen Folbigg wants her convictions for killing her four children overturned.
Folbigg was convicted in 2003 and ordered to serve a minimum 25-year sentence for the suffocation murders of three of her children and manslaughter of a fourth.
The children, Caleb, Patrick, Sarah and Laura, died between 1989 and 1999 at ages ranging from 19 days to 18 months.
But Mr Bathurst found Patrick's death was likely caused by a neurogenetic disorder rather than suffocation, while there were also plausible explanations for the deaths of Sarah and Laura.
"Although no identifiable cause of Caleb's death was identified (the other evidence means) that in his case the reasonable possibility that he died of unknown natural causes has not been excluded," he said.
Folbigg was released after the inquiry heard there was credible evidence her children could have died from natural causes and the Director of Public Prosecutions accepted there was reasonable doubt about her guilt.
NSW Attorney-General Michael Daley in June said he accepted that preliminary finding and had recommended Governor Margaret Beazley grant an unconditional pardon.
Mr Bathurst said he had agreed to a request from Folbigg to refer her case and his report to the NSW Court of Criminal Appeal to consider quashing her convictions.
In a statement, her lawyer Rhanee Rego said she welcomed the referral and the inquiry's conclusions.
"Today, and every day, Kathleen's thoughts are with her children," she said.
Ms Rego noted that Mr Bathurst described Folbigg as a "loving and caring mother", a finding she said "reinforces a personal truth that Kathleen has held in her heart for more than two decades".
The 55-year-old's legal team previously indicated the next step after her release would be to have her convictions overturned, followed by seeking compensation from the state.
A spokeswoman for Mr Daley said it would be inappropriate for the attorney-general to comment further on the case as it had been referred for appeal.
The government can opt to make an ex-gratia payment to Folbigg on the basis that she has suffered at the hands of the state, however the option will only be considered once she has exhausted all legal options.
- with AAP
