Kathleen Folbigg – jailed for two decades over the deaths of her four children – is ACQUITTED: Here’s the new theory of how they died

After spending more than 20 years in prison for the deaths of her four children before being pardoned and released, Kathleen Folbigg has now been exonerated.

The NSW Court of Criminal Appeal quashed her convictions on Thursday morning as applause filled the court.

The 56-year-old was given an unconditional pardon and released from prison in June after an investigation found there was reasonable doubt about her guilt following new scientific discoveries.

In a final report released in November, investigating commissioner Tom Bathurst KC found there was an 'identifiable cause' for three of the deaths and that Folbigg's relationship with her children did not support the claim she killed them.

The report has been sent to the court of appeal. “Although the verdicts at trial were reasonably open based on the evidence available, there is now reasonable doubt as to Ms Folbigg's guilt,” NSW Chief Justice Andrew Bell said on Thursday.

'It is appropriate that Ms Folbigg's convictions… be quashed.'

The appeal judges agreed with Bathurst's finding that the mother's diary entries – controversially used during her trial to secure her convictions – did not contain reliable admissions of guilt.

Folbigg consistently told police and a previous investigation that the entries reflected her feelings of failure as a mother after the deaths of three of her children.

She was sentenced in 2003 to a minimum of 25 years in prison for the suffocation murders of three of her children and the 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.

“(I) grieve for my children and I miss them and love them dearly,”

Folbigg said in a video after her release in June.

A rare genetic variation was a “reasonably possible cause” of Sarah and Laura's deaths, according to cardiology and genetics experts.

Myocarditis, an inflammation of the heart, was another possible cause of Laura's death. Patrick may have died from a neurogenetic disorder, which could also have put him in hospital before his death, experts told the inquiry.

Reasonable causes for their deaths undermined the tendency reasoning used to convict Folbigg of Caleb's manslaughter.

Folbigg's lawyers have previously indicated the possibility of seeking damages from the state.