He said 300 refugees and asylum seekers continued to remain in the decommissioned processing centre, where there had been no distribution of food and water for three weeks and medicines ran out last week.
"The refugees are sitting peacefully and immigration and police are asking them to leave the prison camp", tweeted Behrouz Boochani, one of the men inside the Manus Island center who is defying attempts by Australia and PNG to close the facility.
An Australian of the Year is chosen annually by a government-appointed board to celebrate the person's achievements and contributions to society.
"The Australian taxpayers have paid about $10 million for a new facility and we want people to move... it's like the tenant that won't move out of the house when you build a new house for them to move into".
"So many police mobile squad and immigration officers came inside the prison camp".
"And obviously, it's in the end an issue for PNG police and the authorities up there but is an operation involving police in the centre this morning".
Mr Boochani said police were searching rooms, have been taking the men's phones, and saying they have an hour to leave.
Hundreds of men have refused to leave the Manus Island centre since it was shut down on 31 October, citing fears for their safety.
They also say the three transition centres are not fully operational, with a lack of security, sufficient water or electricity.
Under a controversial policy, Australia has detained asylum seekers who arrive by boat in camps on Manus Island and Nauru, a small Pacific nation.
Canberra has strongly rejected calls to move the refugees to Australia and instead has tried to resettle them in third countries, including the United States.
The camps' conditions have been slammed by human rights groups amid reports of widespread abuse, self-harm and mental health problems.
"We believe it is time to stop the unacceptable and internationally criticised treatment of the refuges on Manus Island, who, though innocent of any crime, have been incarcerated and now abandoned there", the letter reads.
The Australian Medical Association appealed to the government and hundreds of protesters marched in Sydney in support.