High-profile wrongfully convicted duo Kathleen Folbigg and Lindy Chamberlain-Creighton have signed an open letter calling for changes to so-called "no body, no parole" laws.
Legislation denying murderers a chance at parole if they don''t help authorities find the bodies of their victims passed NSW parliament in 2022 following Chris Dawson's conviction for killing his wife, Lynette.
Her body has never been never been found, meaning he is unlikely to be eligible for release until 2046 after his appeal to the highest court in NSW was rejected on Thursday.
Similar non-parole laws have been introduced in every other state and territory except for Tasmania and the ACT.
But opponents of the laws cite a "devastating impact on the wrongfully convicted", suggesting they are "disastrous" for a prisoner trying to assert their innocence.
An open letter against the parole regulations had been signed by 116 people by Monday morning, including lawyers, academics and campaigners for justice reform.
"'No body, no parole' laws in NSW deny parole to any incarcerated person convicted of a homicide offfence who does not satisfactorily co-operate in police investigations or other actions to identify their victim's location," the letter read.
"Wrongfully convicted people, however, cannot satisfy this precondition for parole ... while the extent of wrongful convictions in Australia can only be estimated, Kathleen Folbigg's recent pardon after serving 20 years in prison is a stark reminder about their reality."
Ms Folbigg was freed a year ago after new scientific evidence cast reasonable doubt over her convictions for the deaths of her four children.
Her barrister Robert Cavanagh said demands for killers to provide full details of their crimes were understandable, but he added that sentencing judges could take their co-operation into account in place of the laws.
"If politicians want to improve the criminal laws they should do so based on good evidence, not understandable emotion," he told AAP.
"Without good evidence for change, bad laws are made and the suffering of wrongly convicted people is greatly increased ... there is insufficient evidence that the change to the law is based on evidence showing it will help find the missing.
Dr Cavanagh pointed to Ms Chamberlain-Creighton's case as an example of where "no body, no parole" laws would have harmed an innocent person.
She spent four years in prison for the 1980 murder of her baby Azaria before the infant's matinee jacket was found in a dingo lair near Uluru, in a killer blow to the prosecution's case.
The open letter calls on the NSW government to restore the State Parole Authority's discretion to release an offender in "no body, no parole" cases based on an assessment of the relevant factors, particularly any risks posed to the community.
A NSW government spokesman pointed out the laws only required offenders to co-operate in a search, rather than actually find the remains.
Offenders were still released on the completion of their sentences if they did not help, he added.
But the letter noted those wrongfully convicted already faced a dilemma with parole, which they were often denied if they refused to undertake pre-release programs that required them to admit responsibility and express remorse.
