Photos of a cage used to restrain a young boy with autism at a Canberra school have become public, against the ACT Education Minister's wishes.

Constructed of blue metal pool fencing, the two-metre by two-metre cage clearly has a roof and a rear door — which was able to be latched shut.

The cage was built by an external contractor with $5,195 of school funds.

It stood for 14 days at a school in Canberra's south before it was ordered to be dismantled in March by the ACT Education and Training Directorate.

View from inside the classroom of the cage in which a boy with autism was kept. ( Supplied )

On Tuesday ACT Education Minister Joy Burch called the cage "disgusting" and said a government investigation had found the school's principal was solely responsible for approving its construction.

The principal was stood down from her role and will not be able to teach in a government school again, however she will continue working for the Education and Training Directorate.

On Wednesday Ms Burch slammed Canberra media organisations for publishing photos of the cage.

Ms Burch said she believed publishing the photos was heartbreaking for the boy's family and emotionally damaging for other parties involved.

"I accept that the community rightly wanted answers as to how such a structure came to be," she said in a statement.

"Information about this is now freely available to the public [via the directorate's website].

"Publishing [these photos do] not assist in getting to the truth or add any more insight as to why it was constructed."

Parents had previously complained they were kept in the dark about the investigation into the cage and when it was going to be finalised.

Ms Burch has acknowledged that the time taken to complete the investigation had been extremely frustrating.

"The length of time this has taken did not meet community expectations or my expectations as minister," she said.