Children Out of Immigration Detention, or ChilOut, says it is deeply concerned about an Australian government plan which may mean child refugees living in Nauru are resettled in Cambodia.
The first refugee is expected to be flown from Nauru to Phnom Penh this week under a controversial 30 million dollar resettlement deal.
A ChilOut spokesperson, Claire Hammerton, says Australia has an obligation under the United Nations Convention on the Rights of the Child to ensure the best interests of children are guaranteed.
"Sending children and families to a country that has a long history of human rights abuses and where there is a real risk that children sent there will be subject to abuses and not afforded their basic human rights, we would say it is simply not in the best interests of the child and simply should not occur."
Claire Hammerton says there are about 103 children in immigration detention on Nauru, many more found to be refugees and living with their family in the community, and about 28 unaccompanied minors.