Kathleen Folbigg: Mum pardoned for baby deaths claims win for science

An Australian woman convicted of killing her four infant children says a decision to pardon her after 20 years is "a victory for science" and "truth".

Kathleen Folbigg was released from prison on Monday after an inquiry upheld new evidence which cast "reasonable doubt" on her convictions.

Originally accused of smothering her children, the evidence suggested they died due to rare genetic abnormalities.

The 55-year-old said she was "humbled" and "grateful" to be free.

"For the past 20 years I have been in prison, I have forever, and will always, think of my children [and] grieve for my children," she said in a video statement.

Ms Folbigg also thanked her friends and supporters, who in recent years waged a campaign for her case to be reviewed.

"I would not have survived this whole ordeal without them," she said.

Ms Folbigg was met at the prison gates by long-time friend Tracy Chapman, who said she spent her first day of freedom enjoying simple pleasures.

These included a comfortable bed, pizza and garlic bread, and a Kahlua and coke, Ms Chapman told reporters, adding that Ms Folbigg was "in awe" of modern technology such as smartphones.

"There's no hate in Kath's heart. She just wants to live a life she missed for the last 20 years and move on," she said.

Ms Folbigg would now seek to have her convictions quashed in the Court of Criminal Appeal, lawyer Rhanee Rego said.

"If Australia really wants to make some good from a tragic story, they'll seriously consider reviewing the system of post-conviction review," she said, adding that it had taken too long for Ms Folbigg's case to be scrutinized.

Ms Folbigg, who always maintained her innocence, made two unsuccessful appeals against her conviction and an earlier inquiry upheld the guilty verdict.

But on Monday the New South Wales (NSW) attorney general said Ms Folbigg had been granted the unconditional pardon due to another recent inquiry into her case.

That inquiry, led by retired judge Tom Bathurst, heard all four children could have died from natural causes.

A team of immunologists found that Ms Folbigg's daughters shared a genetic mutation - called CALM2 G114R - that can cause sudden cardiac death.

The heart condition, known as calmodulinopathy, is so rare that only 134 known cases have been detected worldwide.

Evidence was also uncovered that her sons possessed a different genetic mutation, linked to sudden-onset epilepsy in mice.

The inquiry also heard that the diary entries from Ms Folbigg used in her original trial should not have been accepted as admissions of guilt.

Her ex-husband, Craig Folbigg, had contacted police after reading diary entries, which prosecutors later argued implied she had harmed the children.

He maintains she is guilty, and his lawyer said news of her release had "increased the pain and suffering his client had endured for two decades".

Ms Folbigg could eventually claim a substantial compensation payment from the state if her convictions are overturned.

If her appeal succeeds she could take then legal action against the NSW government, or seek a settlement payment from them.