Australia has omitted the number of children in its detention centres abroad in its report about the detention centres.
The Australian government has told SBS only those children detained in Australia are counted while those held in Pacific countries are the responsibility of those governments, despite the centres being set up as part of an Australian immigration policy.
The report says more than 1,600 children are detained in Australia.
The government has confirmed that about 25 children are on Manus Island in Papua New Guinea but did not say how many are on Nauru.
The Director of the Asylum Centre Resource Centre in Melbourne, Jana Favero, says Australia shouldn't defer responsibility.
"We choose who goes there, we fly the people who are there, we are paying the service providers such as Salvation Army, IHMS for medical, on those two islands yet we say that we don't have any responsibility for giving figures. It's very convenient for them at times to say it's a sovereign nation, we have no control."