The Queensland government is appealing the nine-year jail sentence handed down to the man who killed Caboolture toddler Mason Jet Lee in 2016.
Attorney General Yvette D'Ath said Twitter on Thursday she has lodged an appeal against the manslaughter sentence given to William Andrew O'Sullivan on August 30.
"Today an appeal has been lodged in the Mason Jet Lee case on my behalf after I gave consideration to the advice provided by the Director of Public Prosecution," Ms D'Ath later told journalists.
"The grounds on which this appeal has been lodged is that we believe the sentence is manifestly inadequate and on that basis this appeal is being progressed."
Ms D'Ath said she wouldn't comment any further as the matter went through the legal process.
O'Sullivan, 37, was also convicted of child cruelty after failing to seek medical care when the boy suffered a broken leg and severe anal injuries about six months before he was killed in June 2016
The sentence handed down by Chief Justice Catherine Holmes means he could walk free in four years with time already served.
Mason's final hours were spent wrapped in a towel, lips blue, making grunting noises.
Traces of methamphetamine were found in his blood after he died.
O'Sullivan, who had long battled an addiction to drugs, particularly ice, tried to cover up his involvement in the little boy's death by blaming paramedics for taking too long to respond.
But they had taken only six minutes to arrive after being called by a friend.
He also lied to police by saying he found Mason with his lips blue and mouth clamped on a bottle before calling an ambulance and later claimed his 12-year-old "serial killer" daughter may have beaten him.