Security guards on Manus Island have reportedly assaulted a refugee for not returning to the East Lorengau transit centre by the 6:00pm curfew.

The Iranian man was at a local restaurant at around 10:00pm when guards from the transit centre assaulted him and took him back to the Australian-funded accommodation.

"Suddenly some PNG [Papua New Guinea] immigration people injured him and very forcibly they took him to car for going back to his accommodation," said a source, speaking on condition of anonymity due to the sensitive matter of refugee issues on the island.

"[They] hit him and his face become dark blue."

Manus Island Provincial Police Commander Alex N'Drasal confirmed the assault took place and said he was interviewing the PNG guards believed to be involved.

The Lorengau General Hospital told the ABC on Tuesday it had not treated a refugee for assault-related injuries in the last 24 hours.

The refugee is one of a small group of men who have had their asylum claim processed, have left detention and are awaiting permanent resettlement in another part of Papua New Guinea.

However, the PNG Government has not formed a policy for resettling refugees and is giving them no indication how long they will be kept on Manus Island.

While free from the Australian-run detention centre on the Lombrum Naval Base, the refugees are expected to return to the East Lorengau transit centre between 6:00pm and 6:00am.

Legal basis for curfew unclear

"Where is [the] law, I don't know?" asked one refugee at the East Lorengau centre.

The ABC is seeking comment from PNG's Ministry of Immigration and Australia's Department of Immigration and Border Protection.

Last week, PNG passed amendments to laws dealing with foreigners in immigration detention.

"The Migration [Amendment] Bill provides expanded powers to manage refugee relocation centres and places of immigration detention, and introduces for the first time a clear definition of immigration detention," Foreign Minister Rimbink Pato said in a statement released on May 28.

"Minister Pato also stated that the Government is working to ensure that public servants and officers, as well as contracted security staff, have the powers and legal certainty necessary to discharge these responsibilities."

The night curfew on Manus Island is part of wider restrictions for the refugees awaiting resettlement.

In March, Iranian refugee Reza Mollagholipour was denied permission to leave Manus Island to attend job interviews he had organised in PNG's capital Port Moresby.

Earlier this year Mr Mollagholipour expressed optimism about finding a job and starting a new life in Papua New Guinea but in recent weeks has told the ABC he is losing hope.

PNG's prime minister Peter O'Neill said last month that 129 asylum seekers had been granted refugee status, while more than 400 had returned to their home countries.

To date, no refugee has been resettled in PNG.