Australia has agreed to improved oversight of immigration detention centres, prisons, juvenile justice centres and psychiatric facilities under a deal signed with the United Nations.
The Turnbull government on Friday ratified an optional international convention against torture and other cruel, inhuman and degrading treatment or punishment.
Australia pledged to sign the protocol as it competed for a seat on the UN's Human Rights Council. Its three-year term will begin next year.
"Ratification is not the end, but the beginning of an ongoing discussion about oversight and monitoring," Foreign Minister Julie Bishop and Attorney-General George Brandis said in a statement.
"Ratifying OPCAT demonstrates Australia's unwavering commitment to international scrutiny and accountability," the pair said, adding they would work with the states and territories to fulfil the obligations.
The Australian Human Rights Commission has welcomed the development, saying places of detention are often hidden, allowing abuse to go unnoticed.
But the Human Rights Law Centre said Australia must accept scrutiny of its offshore facilities on Manus Island and Nauru.
"The whole purpose of this treaty is to prevent abuse through transparency," legal advocacy director David Webb said.
"It defeats that purpose if our government can just decide to keep its deepest darkest sites of misery and suffering deliberately shielded from scrutiny."
