Manus Island police say there are no suspicious circumstances surrounding the death of Hamed Shamshiripour, although some asylum seekers contest this.
The 28-year-old was found dead in bushland near a primary school on Monday.
Mr Shamshiripour's family has sought legal advice. They say they want an inquest conducted into his death in Australia and for an independent autopsy to be done.
The family's lawer, George Newhouse told SBS World News the man's family also want Mr Shamshiripour's body to be repatriated to Iran.
“The family want justice,” Mr Newhouse said.
“When a person dies in custody there is automatic grounds for an inquest in this country and under PNG law.”
A letter published by , shows the Australian Border Force's chief medical officer Dr John Brayley knew about Mr Shamshiripour's mental health problems a year ago.
Hamed Shamshiripour's ID card. Source: Supplied
“Our leaders are implicated in Hamed's death," Mr Newhouse said.
"Government officials knew about his fragile condition and they left him to die."
He said his son had complained about mistreatment by the Australian government and a lack of action regarding his mental conditions.
A memorial has been held inside the Manus Island detention centre.
It comes amid concerns about another refugee who reportedly fractured his skull and has reportedly been transported to Australia in a critical condition.
Iranian-Kurdish asylum seeker and journalist on Manus Island, Behrouz Boochani, has been tweeting updates about the man's condition.
The UNHCR has warned of an escalating crisis on Manus Island ahead of the forcible closure of the detention facility by October.
Australian and Papua New Guinea immigration authorities are trying to move refugees to a transit centre, but they have been refusing to go, saying they fear for their safety in an open facility.
The Refugee Action Coalition's Ian Rintoul told a rally in Sydney on Wednesday that refugees and asylum seekers on Manus Island should be brought to Australia.
“There is only one third country that has the responsibility for the people who have been sent to Manus Island and that's Australia,” Mr Rintoul said.
Refugee Action Coalition rally in Sydney on August 9. (SBS World News) Source: SBS World News
The Department of Immigration and Border control has not responded to SBS's request for comment and further information.
