The ABC has apologised for incorrectly reporting that a five-year-old boy on Nauru had allegedly been raped.
"ABC News apologises for the errors and confusion," the broadcaster said in a statement on Monday.
The broadcaster said the source, the treating doctor, told the reporter about two cases and the story incorrectly used quotes about an older child in referring to the younger child.
The doctor quoted in an incorrect ABC report about a five-year-old boy being raped in the Nauru detention centre says she provided accurate information and stands by her comments about children in detention.
But the broadcaster admits it misinterpreted the details and has apologised for incorrectly reporting the rape allegation.
The ABC said the doctor told its reporter about two cases but the story mistakenly used quotes about an older child in referring to the five-year-old.
Immigration department official Cheryl-anne Moy told a senate hearing on Monday the matter involved a child who was at least 10 and was assaulted by a child two years older. Ms Moy said there was no allegation of rape.
Paediatrician Karen Zwi issued a statement on Monday saying she did not want to be "drawn into the age of the child concerned for confidentiality reasons."
"As a paediatrician I have provided information which was factually accurate," Dr Zwi said.
"A child is a child. I stand by the statements I have made with regard to children in detention."
Dr Zwi told the ABC the child suffered serious mental health problems after the alleged incident.
The claim a five-year-old boy had been raped was used by refugee advocates, the Greens, members of the medical profession and some media to argue against returning a group of 267 asylum seekers to Nauru following a failed High Court challenge.
The ABC last week said the boy faced the prospect of being returned to the offshore detention centre where his attacker remained.
However, Immigration Department head Michael Pezzullo rejected the story in evidence to a Senate committee hearing on Monday.
"There is no five-year-old child, it's a figment," Mr Pezzullo said.
The Human Rights Law Centre, which last week lost a High Court bid to prevent asylum seekers, including children and babies, being sent back to Nauru after receiving medical treatment in Australia, confirmed on Monday the child involved was not affected by the High Court ruling.
"The child at the centre of rape allegations is not a client of the Human Rights Law Centre and is not one of the 267 people linked to last weeks High Court challenge," the HRLC said in a statement.
The HRLC also said it was not involved in the report of the alleged rape, aired on ABC television's 7.30 on February 2.
"Neither the HRLC or (activist group) GetUp was involved in the decision to take the story to the media," it said.
Mr Pezzullo criticised refugee advocates for making the claim and pointed to media advocacy "parading as journalism".
Dr Zwi said all children had a right to expect "safe and nurturing environments".
"That is not currently happening for many children in immigration detention."