The head of Amnesty International says the group has been denied access from inspecting conditions at Australia's detention centre on Nauru.
Its secretary general Salil Shetty has told Australian television that after previous visits to the camps, Amnesty reported about conditions of overcrowding, ill health and violence against the asylum seekers.
Mr Shetty says he will be in Australia next week to point out that Canberra is in violation of international standards, which he says Australia needs to correct itself.
He also says Australia has to stop keeping children in detention centres.
Meanwhile, the UN High Commissioner for Human Rights, Zeid Ra'ad Al Hussein, has said he is dismayed that Australia, sends people on boats intercepted at sea to detention centres where conditions are inadequate.
Australia has repeatedly dismissed criticism of its practices in Nauru and Papua New Guinea.
In March, the Australian Prime Minister Tony Abbott said the country was sick of being lectured by the United Nations over its treatment of asylum seekers.