Immigration Minister Scott Morrison will give evidence at an inquiry into the treatment of children in detention centres in Canberra on Friday.
The national inquiry by the Australian Human Rights Commission has heard claims of self-harm, mental health problems and medical neglect among children in offshore detention.
Mr Morrison has been critical of commission's president, Professor Gillian Triggs, saying some of her allegations of cruelty in these centres are "sensational".
He is expected to be grilled about the federal government's policy along with two of his advisers.
The minister this week announced that about 150 asylum-seeker children in mainland detention centres would be released into the community on bridging visas by the end of the year.
About 700 children will remain in detention centres, including those in Nauru and on Christmas Island.