An Iranian refugee who was deported from Fiji to Papua New Guinea has been told he cannot receive treatment in hospital until his bail application is heard.

The 20-year-old was being treated at a private hospital for dehydration and mental illness, but is now locked up at a Port Moresby police station.

His application for bail was adjourned today because police prosecutors asked for more time to study the court file.

Sawari's lawyer, Loani Henao, argued the bail application was urgent because of his client's medical condition, but the magistrate ruled in favour of the police.

The bail application is now listed for Friday.

After the hearing police told Mr Henao they would arrange to have doctors treat Sawari inside the police cells.

"He certainly needs medical treatment and some psychiatric assistance," Mr Henao said outside court.

"So between now and then the magistrate thought nothing would happen and decided not to allow him to go back to the hospital for treatment."

The United Nations High Commissioner for Refugees has expressed concern about the treatment of Sawari, saying the agency was "profoundly concerned for his welfare".

"UNHCR has long called for refugees and asylum seekers currently in Papua New Guinea to be moved to humane conditions outside of the country, equally, UNHCR has urged that no refugees or asylum seekers should be returned there," the UNHCR said in a statement.