In a scathing report, the UNHCR said Australia's ''no-advantage'' policy, in which boat people who arrived in Australia after August 13 face transfer to Nauru or Manus Island, was ''inconsistent'' with both countries' responsibility to protect the rights of refugees.

Regional representative Richard Towle told Fairfax on Friday that the transfer of asylum seekers to Papua New Guinea and Nauru ''doesn't relieve Australia of its moral and legal obligations'' under the Refugee Convention.

''If a convention country is going to be sending someone somewhere else, they are responsible for safeguards,'' Mr Towle said.

''In our assessment, on Nauru those protection safeguards are not in place.''

The UNHCR sent a monitoring team to the island earlier this month, on Friday releasing a damning report on the physical conditions faced by asylum seekers, and the unclear jurisdictional and legal environment on the island on Friday.

Under the agreement struck between Australia and Nauru, Nauru is responsible for assessing the asylum claims of detainees on the island. But the UNHCR said there was no ''functional framework'' in place to hear people's claims for protection.

It said there was no freedom of movement for asylum seekers, and that people were not individually assessed for their suitability for lengthy detention.

Indeed, the UNHCR reported that a number of asylum seekers showed signs of having suffered torture and trauma before their transfer to Nauru, and said the capacity of health officials on the island to care for people with complex health and psychological conditions caused by torture and trauma was ''limited''.

The UNHCR reported that conditions at the ''closed and congested'' camp on Nauru were ''harsh'', with little natural shelter from the heat and significant noise and dust from nearby construction activities.

While permanent facilities are being constructed - they are expected to be complete by February - the men slept in shared tents that offered little privacy. Smaller tents slept up to five men, while larger tents slept up to 16.

But the agency reported that asylum seekers were more concerned with the processing of their claims for asylum which, some said, they had been told could take five years to complete.

The report also raised concerns about the delays in processing people's asylum claims.

''What concerns us in all of this is the no-advantage consideration has been used for slowness of process,'' Mr Towle said. ''We think it's inappropriate to use it to suspend or delay due process.''

A spokesman for Immigration Minister Chris Bowen said Australia would continue to work with Nauru on assessing the asylum claims of detainees, and said interviews had begun.