In the dark on Australia's prison system
The United Nations had planned a 12-day visit to monitor places of detention.
91 nations have signed up to OPCAT , the Optional Protocol to the Convention Against Torture.
It aims to protect the rights of people in detention.
But representatives were denied access at multiple centres, and ended the trip ahead of schedule.
Corrective Services New South Wales confirmed U-N representatives were denied access at two prisons yesterday, saying they didn't have prior approval.
The U-N was also denied access to the Queanbeyan Court Cells last week, and said it faced access issues in Queensland as well.
