Aid agency Doctors without Borders has been prevented from entering three new facilities on Manus Island now housing refugees.
Last week, the Papua New Guinea police forced about 400 refugees to give up their three-week protest at the closed detention centre and move to the new accommodation.
Kurdish journalist and refugee Behrouz Boochani said many refugees need medical treatment after being beaten and traumatised by the police.
People were deeply traumatised but had no psychologists to help, he said.
The Papuan police commissioner, Gari Baki has denied the police were violent.
Another Manus Island refugee described cramped conditions in the newly built accommodation.
Abdul Aziz Adam was among those men unable to find a bed.
"Twenty-five guys are still homeless... The transit centre is meant to accommodate at least 290 people but today they put more than 350 [in]," he said.
"They just keep squeezing people together - the rooms are only two metres ... but they put at least four people in each room."
The 25 refugees without beds have been sleeping in a classroom, Mr Adam said.