The case was one of 63 reports of "abuse in care" referred to the commission in the past financial year, a rising number but largely consistent with the 61 such reports in 2014-15, the last time the Public Advocate's full annual report was released.

Public Advocate Jodie Griffiths-Cook said the commission was seeing a growing number of such reports, consistent with the ACT's rising number of children in out of home care.

But she said she could not detail whether the allegations of sexual abuse made about the child's carer were substantiated, or provide any more details about the case to protect the child's privacy.

The report came amid rising delays in child and youth protection reporting such allegations to the commission, with most allegations not reported until four to six months after the original allegation was made to the directorate.

Those delays have forced Ms Griffiths-Cook to issue more than 200 official "requests for information" in the past two years, 121 in 2015-16 and 89 in the past fiscal year, compared to just 14 in 2014-15.

She said the delays were not necessarily indicative of failures to report such cases, rather it could indicate the protection service needing to work through "appraisals" of each case before reporting it.

But she wrote in the commission's annual report such delays "seriously compromised the ability of the Public Advocate to adequately monitor this area of the child protection system".

The report also showed that while the child was originally reported as having suffered abuse, once the commission used its powers to request more of the case file, it "identified a number of concerns relating to sexual abuse".

"The Public Advocate immediately brought these concerns to the attention of the Director-General. A placement change was subsequently enacted for the child," the report said.

The report highlighted the "lack of information" in reports of abuse in care being referred to the commission, leading to a "significant increase" in official requests for more information.

But Ms Griffiths-Cook said such requests had to be made under the Human Rights Act, given the sensitive nature of such information, rather than more informal requests for information.

The commission report also showed some 158 children were taken into care during 2016-17 under emergency provisions warranting the director-general's intervention, with the commission attending 102 related court hearings.

The report also shows the commission inspected the register of strip searches at Bimberi Youth Detention Centre last fiscal year, which showed 78 strip searches conducted of young people that did not identify any contraband.

Ms Griffiths-Cook said that she was aware of processes before strip searches are completed that allow a detainee to declare any contraband they may have and to surrender, but that the commission did not have access to data on how many times items were surrendered.

After The Canberra Times reported on unlawful "squat and cough" searches being conducted at the detention centre in March, Ms Griffiths-Cook inspected the register in April, after which the directorate "discontinued" the practice.