Advocates and refugees say they are concerned that police in Papua New Guinea have ruled out foul play in the death of a man detained on Manus Island.
Hamed Shamshiripour, a 31-year-old from Iran, was the fifth refugee to die on Manus Island since 2013.
On Monday night, police commissioner Gari Baki said there were no suspicious circumstances surrounding the death, after Mr Shamshiripour's body was found hanging on Monday morning.
He said the body was at the detention centre's morgue and a full autopsy was expected soon.
But Ian Rintoul from the Refugee Action Coalition said Mr Baki's declaration was hasty and suspicious.
Mr Rintoul said photos of Mr Shamshiripour's body showed foul play could be involved.
He said an independent autopsy and investigation needed to be conducted to establish the cause of death.
The Kurdish journalist and Manus detainee Behrouz Boochani said some of the centre's 800-odd residents also thought the death could be suspicious.
He said they supported calls for an independent investigation.
Refugees held a candlelit vigil on Monday night at the center in place of their ongoing protest action against water and power restrictions.