The man serving a life sentence for killing 12-year-old Tiahleigh Palmer is in a critical condition in a Queensland hospital.
Rick Thorburn was convicted of murdering his foster daughter and dumping her body in a Gold Coast River in 2015.
He was rushed to Princess Alexandra Hospital on Saturday morning after being found unresponsive on the floor of his cell at Wolston Correctional Centre in Wacol.
On Monday, a Metro South Health spokeswoman said Thorburn remained in a critical but stable condition.
He was 57 when he pleaded guilty in 2018 to charges of murder, perjury, interfering with a corpse and attempting to pervert the course of justice.
He was sentenced to spend at least two decades behind bars and will be eligible for parole in 2036.
Thorburn's wife and two sons were also jailed for their involvement in Tiahleigh's death.