The outgoing president of the Australian Human Rights Commission says being barred by the government from its offshore detention centres is deeply disturbing.
Professor Gillian Triggs finishes her controversial term as president at the end of July.
During her five-year tenure, Ms Triggs was attacked by the government after launching an inquiry into children held in immigration detention.
She was banned from Nauru and Papua New Guinea's Manus Island where Australia detains maritime arrivals, but "asserted jurisdiction" over complaints received by detainees.
"We've negotiated on behalf of the men and the families that have been held on Nauru with the government. In some cases ... with some success, in others not," she said.
"But I have not been able to visit Manus or Nauru myself. And the reason for that is the Australian government will not permit me to do that as president of the commission."
Formerly a professor of international law at Sydney and Melbourne law schools, Ms Triggs has been outspoken on the government's obligation not to forcibly return, or refoul, asylum seekers to countries where they face persecution.
She said data analysed by the commission showed asylum seekers on Manus Island were at risk of 'constructive refoulement' by being coerced into accepting repatriation.
"I think that all the evidence supports the view that the conditions in which they're being held are overcrowded, ultimately dangerous and well below proper standards for detention. And of course the indefinite nature of their detention has been extremely worrying.
"I do fear that the length of time for which this situation has been allowed to continue rather demonstrates the point that Australia and Papua New Guinea have tried deliberately to encourage the men to go back to the countries from which they came and where they allege persecution."
Despite the government's insistence it was not liable for asylum seekers it detained in other countries, Ms Triggs said the contrary was true under international law.
"The Australian government has taken a very blinkered view of their responsibility," she said.
"They've said over and over again that the treatment of the men, refugees and asylum seekers on Manus, is a matter for the sovereign country of Papua New Guinea, which is a technical argument which completely fails to acknowledge the international law principal ... of the International Court of Justice, that to have effective control or a measure of effective control will sheet responsibility home to the Australian government as well as the PNG government."
Ms Triggs will be succeeded as president of the Human Rights Commission by the law professor and current president the Australian Law Reform Commission, Rosalind Croucher.