New South Wales Attorney-General Mark Speakman says there will be an inquiry into the convictions of serial killer Kathleen Folbigg.

Folbigg was found guilty by a jury in 2003 of the murder of her three young children and the manslaughter of another.

Governor David Hurley has appointed the former chief judge of the District Court, the Hon Reginald Blanch AM QC, to conduct the inquiry.

“I have formed the view that an inquiry into Ms Folbigg’s convictions is necessary to ensure public confidence in the administration of justice,” Mr Speakman said today.

Mr Speakman said the “immensely difficult decision” had been explained to Folbigg’s former husband Craig.

He apologised for the “renewed distress and pain” the family will endure throughout the probe.

“Ultimately, my job as Attorney-General is to ensure public confidence in the administration of justice in NSW,” Mr Speakman said.

Folbigg was initially sentenced to 40 years in jail but it was reduced to 30 on appeal, with a non-parole period of 25 years.

Mr Speakman said she would remain incarcerated during the course of the inquiry, which is estimated to take between six and 12 months.

The matter may be forwarded to the Court of Criminal Appeal if the probe finds there is reasonable doubt around Folbigg’s convictions.

-ABC