Education Minister Joy Burch has put pressure on the head of the education department, criticising delays in an investigation into a Canberra school's decision to erect a cage to hold a student with autism.
Facing the growing criticism over the delayed report by an independent delegate, Ms Burch said she had expressed "strong concerns" to Education Director-General Diane Joseph about the investigation's timeliness and impact on the family of the child and wider school community.
Announcing the investigation in June, Ms Burch said a report would take about three weeks to be completed.
Months later and after a parent from the school spoke out in local media on Thursday, Ms Burch said she was "deeply frustrated with the delays" and had sought answers from Ms Joseph and Education and Training directorate officials.
"I had hoped it would be completed in a matter of weeks, and as such this is what I told the community.
"I have sought and been given regular updates about the progress of the investigation, but I have not yet been provided with details of the findings," Ms Burch said.
"Frankly, I expect better. I understand that a conclusion is imminent, and we all welcome that."
The discovery of the cage in a Canberra primary school was first announced in April.
The cage was used as a withdrawal space for a 10-year-old boy with autism and drew widespread criticism, including from Ms Burch, autism advocates and the Australian Education Union.
In recent weeks the government has declined to answer questions about who had planned and constructed the cage, if it had been authorised, how it was built and paid for, and if the directorate was aware of its use in the classroom.
Ms Burch has not released terms of reference for the investigation, while the school principal has been withdrawn and placed on administrative duties within the directorate.
On Thursday she said advice received from officials suggested it may not be possible for all aspects of the investigation report to be made public after being received by the government.
"However, I am committed to providing the public all the information I can, within privacy and legal constraints, to ensure the public maintain confidence in our education system and our public schools," she said.
Opposition education spokesman Steve Doszpot placed blame for the delays with the minister alone.
"It's now five months since it was announced and the community is still no closer to hearing about what happened and why," he said.
"This is despite repeated hollow commitments from Joy Burch that the investigation has been near completion. Even the terms of reference I've requested haven't been produced."
Mr Doszpot accused Ms Burch of being evasive in public comments about the investigation.
In June the pair sparred on the issue in a budget estimates hearing, with Ms Burch accusing the Liberal opposition of mischief making or a "complete disregard for the people involved".
Last month she said the investigation report was "close" to being released.