A woman previously branded as "Australia's worst female serial killer" has been exonerated of the charges related to the deaths of her four children.

The New South Wales Supreme Court overturned Kathleen Folbigg's convictions on Thursday, citing that the evidence originally used to convict her was deemed "not reliable."

After spending two decades in prison, the 56-year-old had been granted a pardon by the state government in June.

Maintaining her innocence throughout, Ms. Folbigg's case has now been recognized as one of the most significant miscarriages of justice in Australian history.

The allegations centered around the abrupt deaths of her four children—Caleb, Patrick, Sarah, and Laura—each passing away unexpectedly between 1989 and 1999, at ages ranging from 19 days to 18 months. Prosecutors during her trial contended that she had smothered them.

In 2003, she received a 40-year jail sentence for the murders of Sarah, Patrick, and Laura, as well as the manslaughter of her first son, Caleb.

Earlier this year, a landmark inquiry into her case concluded there was reasonable doubt over Ms Folbigg's guilt, due to scientific evidence that her children could have died of natural causes because of incredibly rare gene mutations.

Too bad

Hmm very bad