Authorities should question the fitness of parents whose 10-week-old baby girl ended up in a coma after swallowing a tablet, thought to be ecstasy, the Queensland opposition says.
Opposition child safety spokeswoman Jann Stuckey, a former paediatric nurse, criticised the decision of the Queensland Department of Child Safety (DOCS) to let the baby remain with the pair.
The decision appeared to be a "convenient" option for an overstretched department dealing with a child from interstate, she said.
"Even if this (tablet) was accidentally given, alarm bells should be going off as to the fitness of these parents to care for this child," she told AAP.
The baby was returned to her Victorian parents, who were holidaying in Queensland's far north, after they were granted bail in Cairns Magistrates Court on Tuesday.
The pair were charged with grievous bodily harm and possession of a dangerous drug.
The baby was rushed to Cairns Base Hospital on Sunday in a critical condition after suffering a seizure and was placed in an induced coma in intensive care.
She was released from the hospital into her parents' care on Tuesday.
Although Ms Stuckey only knew the details of the case that had been made public, she said it appeared DOCS had returned the baby because the parents were from interstate and the department's resources were already stretched.
"What I'm reading from this is that it was a convenient decision to flick it back to Victoria," she said.
"They don't want any more on their books."
Ms Stuckey said the case showed the need for a national child safety system so children could be monitored as they moved interstate.
"What monitoring will be done? What guarantee have we got when this child returns home."
Ms Stuckey said parents should show great caution when giving medication to infants.
DOCS director Norelle Deeth has defended the department's decision to let the baby stay with her parents and said it consulted with a wide range of professionals before making a decision of this nature.
She said DOCS also worked closely with its interstate counterparts to ensure the safety of children.