An Australian human rights organisation says refugees in Papua New Guinea and their families will continue to suffer unless Canberra restores aid and evacuates them.
Almost 50 men were forced to Manus Island in northern PNG after seeking safety in Australia more than a decade ago.
They continue to live in limbo in Port Moresby after PNG's humanitarian services cut support due to alleged non-payment of bills by the Australian government.
In October last year, an Australia Department of Home Affairs spokesperson said in PNG had taken over the "exclusive independent" management of the remaining refugees in December 2021.
The spokesperson, at the time, said the funding arrangement was agreed confidentially, and details remained confidential.
Charities, individuals and refugee advocacy groups have been financially supporting the men but say donations have dried up.
They say they are now forced to make the "gut-wrenching" decision to stop providing financial support to the group by mid-September.
Asylum Seeker Resource Centre (ASRC), which provides support to asylum seekers, is calling on the Australian government to "to avoid an Australian-made human catastrophe on PNG soil".
"After 11 years of unimaginable cruelty, pain and anguish, the refugees simply cannot bear yet another impossible challenge that they have no control over," Heidi ASRC's detention advocacy caseworker for PNG, Heidi Abdel-Raouf, said.
"The Albanese government can and must fix this problem quickly to avoid an Australian-made human catastrophe on PNG soil."
The Australian government announced in early July it would work with the PNG government to reinstate support to the at-risk cohort, many who are extremely unwell, but it has given no indication of what the support will involve and when it will restart.
Charities and humanitarian organisations working closely with the PNG men and their families, say the situation is now beyond critical and that lives will be lost unless the Australian Government urgently steps up to its responsibilities.
The men and their families have been suffering the compounding impacts of years of trauma, medical neglect, violence and abuse, poor nutrition and substandard living.
A recent health report by the ASRC confirmed that 100 percent of the refugees still held in PNG suffer from some form of physical health conditions and 40 percent suffer chronic suicidal ideation and a history of suicide attempts.
The ASRC said the only lifeline for the remaining refugees and their families, if the Australian government refuses to reinstate support and evacuate people to safety, is resettlement to New Zealand, US and Canada.
However, resettlement to-date has been slow with some people left waiting several years.
It said many refugees are now becoming too unwell to engage further in the resettlement process.