Staff involved in the case of Mason Lee before the innocent toddler died will be investigated - as the heartless moment his vile stepfather told boy to shut up before belting him is revealed
- Mason Jet Lee's stepdad hit him so hard that his small intestine split inside
- His mum and stepdad refused to seek help, leaving him to die five days later
- Child safety officers failed to regularly visit Mason leading up to his 2016 death
- Premier Annastacia Palaszczuk said 21 child safety officers will be investigated
- She has referred the matter to the Public Service Commissioner to look over
- The coroner revealed the shocking moment Mason was belted on Tuesday
Child safety officers who failed to regularly visit toddler Mason Jet Lee before he died will now be investigated.
A 22-month-old boy, Mason died of an infection in Caboolture, Queensland, in June 2016 after his stepfather William O'Sullivan belted him in the abdomen so hard it ruptured his small intestine.
'The handling of Mason's case was a failure in nearly every possible way,' deputy state coroner Jane Bentley said during her findings on Tuesday.

Mason Jet Lee (pictured) died of an infection in Caboolture, Queensland, in June 2016 after he was struck in the abdomen by his mother's boyfriend, William O'Sullivan. Child safety officers will now be investigated

Queensland Premier Annastacia Palaszczuk (pictured) said the Department of Child Safety will be investigated by the Public Service Commissioner in Brisbane on Wednesday
'I've spoken with my Director-General today and I have asked that the coroner's report be forwarded to him to go to our Public Service Commissioner,' she continued.
'The Public Service Commissioner must look at all of the staff that have been involved.
'We just need to go through that report very carefully and we need to make sure that we adopt the recommendations that the deputy coroner has made.'
There were 21 child safety staff involved with Mason's case. Three people left of their own accord while nine have since been disciplined over the ir handling of toddler's case.
Ms Palaszczuk's pledge to investigate the Department of Child Safety comes after deputy coroner revealed the shocking details of Mason's death on Tuesday.
Ms Bentley presented an audio recording that pinpointed the exact moment Mason was belted by his stepfather O'Sullivan on June 6, 2016.

Baby Mason Jet Lee was neglected and abused by his mother and stepfather William O'Sullivan. There were 21 child safety staff involved in Mason's case


William O'Sullivan (right) and Mason's mother Anne Maree Lee (left) pleaded guilty to manslaughter after failing to get the toddler medical treatment
The audio was captured by a CCTV camera that O'Sullivan had installed.
In the recording, Mason can be heard crying.
'Oh - shut up', O'Sullivan says, but the toddler continues to wail.
Soon, O'Sullivan begins to scream.
'I find that it was at this time that Mr O'Sullivan struck him forcefully in the abdomen,' the coroner said in the report on Tuesday.
The toddler was whacked so hard that his small intestine split inside him and then became infected.
His mother and stepfather refused to seek help, leaving the little boy to die a terrible, painful death over five excruciating days.
The audio was not heard in the court case against O'Sullivan and Mason's mother, Anne Maree Lee, in which the pair were each sentenced to nine years jail.

It took Mason five days to die, but it was only the latest injury in a long painful history
The coroner said that if any of the Queensland child safety officers tasked with looking after the abused toddler had done their job in the weeks before his death, he may still be alive.
The blow was just one of many serious and painful injuries the neglected 22-month-old suffered in the months before his death in June 2016.
Deputy state coroner Jane Bentley says the child safety department's handling of Mason's case was 'a failure in nearly every possible way'.
More than 20 departmental staff, who were investigated following his death, were found to have acted unsatisfactorily.
Their behaviour reflected the failure of the system as a whole, Ms Bentley said in inquest findings handed down on Tuesday.
She also warned that details about Mason's last days would be distressing.
'I include it in the findings not to shock or upset, but in recognition of the fact that these things happened to this little boy whilst he was a child in our community,' she told Brisbane Coroners Court.
An autopsy found Mason's death was caused by an infection from internal injuries similar to those seen after car accidents.
He had dozens of other injuries, including a fractured coccyx, extensive bruising and torn skin around his anus.
Mason's declining health in his final days was largely ignored by his mother, Anne-Maree Lee, and stepfather, William O'Sullivan, who are both serving jail sentences for his manslaughter.
The family had been known to the child safety department since before Mason's birth in 2014.

Pictured: Anne Maree Lee with baby Mason. The coroner found no fault with Queensland Police or the Health Department
Mason was hospitalised in early 2016 with injuries a veteran pediatrician described to the inquest as the worst he had seen.
Despite this and the involvement of the police, the department again made the decision to release the toddler back to his family.
In the months before Mason died, child safety officers saw Mason only once for about five minutes in mid-March.
They were required to carry out 12 face-to-face and 12 support contacts with the toddler, Ms Bentley said.
'Had anyone from the department seen Mason in the weeks before his death they could have saved his life.'
Ms Bentley said it was difficult to find any steps that complied with the department's policies and procedures, or were correctly documented.

The coroner said if anyone from the department had seen Mason (pictured) in the weeks before his death they could have saved his life
'The fact that the (ethical standards unit) found that 21 employees of the department involved in Mason's case ... failed to carry out their duties appropriately is indicative of the scale of the failure.'
Ms Bentley made six recommendations, including that the department reviews its policies about how it implements out-of-home care for at-risk children, and provides information to police.
She also advised Queensland Health to allow doctors to escalate child safety cases when they disagree with a decision made by the department.
Child Safety Minister Di Farmer said the child protection system was a difficult and challenging system and she would consider the coroner's recommendations.
'We take a call about a child potentially at risk of harm every four minutes,' she said.
'(But) nobody could possibly read the report that was handed down today and not feel sick to the stomach, to not imagine what that little boy's life was like.'
Ms Farmer said three independent reviews had been held into the department since Mason's death, with significant failings identified.
She said an additional $200 million and more than 200 staff had been allocated to address the issues.