The immigration minister, Scott Morrison, will give evidence at the national inquiry into children in immigration detention on Friday 22 August at a public hearing in Canberra, the Australian Human Rights Commission (AHRC) has confirmed to Guardian Australia.



Morrison will likely give evidence under oath and is expected to be questioned by counsel assisting the inquiry and the AHRC president, professor Gillian Triggs.

Paris Aristotle, chair of the minister’s council on asylum seekers and detention, will also give evidence.

Morrison has recently made public comments discrediting the observations of Triggs during the inquiry, describing her observations of the rising levels of child self-harm and attempted self-harm as “quite sensational”.

Triggs has made a number of visits to detention centres on Christmas Island with an expert delegation of medical professionals who contributed to the observations. The government’s own statistics – obtained by Guardian Australia in a leaked report – show the rate of self-harm in detention soared six times between the introduction of mandatory offshore resettlement last July and January this year.

The minister also responded to a damning submission to the inquiry written by a group of Save the Children workers on Nauru, which documented in forensic detail the “systematic violation” of child asylum seekers rights.

“The minister notes the allegations made in the anonymous submission. The subject matter raised in these allegations is very serious,” a spokeswoman for the minister said.

“The [immigration] department is working with Save the Children and the government of Nauru to determine the veracity of these anonymous claims and to what extent they are credible or relate to current practice.”

Guardian Australia understands the minister’s office had already been briefed on a number of the cases documented in the submission, which include allegations of sexual, physical and verbal assault against children.

“The department has also asked Save the Children if any such concerns have been raised by any of their staff and to provide a response to the government on the allegations made,” Morrison’s spokeswoman said.

Morrison argued that the submission addressed “matters that are outside the terms of reference of the AHRC inquiry” as they related to events on Nauru, a claim that is disputed by the AHRC which does not have extra-jurisdictional powers on Nauru.

The decision to transfer asylum seekers to offshore detention on Nauru is made by the Australian government, who fund all contractors inside the detention centre, which is also staffed with Australian immigration officials as well as Nauruans.

At the third public hearing of the national inquiry, the commission heard shocking evidence from a detention centre worker on Nauru, and of doctors working on Christmas Island.

The inquiry also heard from Dr Peter Young, the former chief psychiatrist working in immigration detention, who said the immigration department asked him to withdraw figures from his reporting on the high rates of mental health issues faced by children in detention.

Young later became the most senior official to condemn Australia’s detention regime in an exclusive interview with Guardian Australia, where he described the process as akin to torture.

“If we take the definition of torture to be the deliberate harming of people in order to coerce them into a desired outcome, I think it does fulfil that definition,” Young said.