Detainees on Manus Island have been threatened with legal action if they refuse to immediately evacuate a compound slated for demolition.
But advocates say it's doubtful anyone will move voluntarily, with the two neighbouring compounds already overcrowded and a nearby transit centre both dangerous and far too small.
Authorities on Papua New Guinea have warned those in the Foxtrot compound of the Manus Island regional processing centre that water, power and cleaning will be cut off imminently.
Detainees have been told they will be personally liable for any risk associated with entering or residing in Foxtrot once amenities are cut.
"Should you not move, you may be in violation of PNG law. Attempt to occupy without consent state property is also subject to legal action," a PNG immigration spokesman told detainees in a letter circulated on Wednesday.
The Manus Island centre will close by the end of October, with decommissioning works well underway and the nearby transit centre being rapidly expanded.
Refugees accepted under a one-off resettlement deal with the United States are expected to begin leaving Manus Island in October.
But advocates argue US resettlement is entirely speculative.
"Refugees and asylum seekers have been unlawfully detained in PNG since July 2013," Refugee Action Coalition spokesman Ian Rintoul said.
"They should be unconditionally released and returned to Australia, instead of being subjected to increased threats of detention and deprivation."
The federal government has for years declared those held in the island camps will never settle in Australia.
