Updated 12 October 2012, 14:38 AEST

The United Nations' High Commissioner for Refugees has raised serious questions about Australia's plan to transfer asylum seekers to Papua New Guinea.

In a letter to the Australian Government, António Guterres says Papua New Guinea does not have the capacity to shoulder the responsibility of processing asylum seekers.

He says the government has indicated it will be handing legal responsibility to PNG authorities, but points out there is no effective legal or regulatory framework in the country to deal with refugees.