The Australian government says it would cost more than 300 million US dollars to upgrade the detention centre for asylum seekers it built on Nauru, should Canberra opt for its re-opening.
The immigration minister, Chris Bowen, says according to estimates by officials who visited Nauru, it would cost 1.6 billion US dollars to house 750 asylum seekers over four years.
The Sydney Morning Herald reports Mr Bowen also as saying it would take an absolute minimum of three months to reopen the Nauru centre.
This comes amid a debate among politicians in Canberra, who are considering reviving a 2001 policy of processing Australia's asylum seekers abroad.
The opposition has been keen to send asylum seekers to Nauru which in turn has been open to a new deal with Australia.
The Australian approach has been widely criticised, including by the United High Commissioner for Refugees, which labelled it a deeply problematic policy, both as a matter of principle and for those refugees and asylum-seekers affected by it