A preliminary investigation says clashes at the Australian asylum seeker detention centre in Papua New Guinea were caused by management's handling of questions posed by asylum seekers.
An Iranian asylum seeker, 23-year-old Reza Berati was killed, and dozens of others were injured during two nights of rioting at the camp on Manus Island last week.
A spokesperson for the PNG police, Dominc Kakas, says the investigation - which is still underway - shows that the unrest happened inside the detention centre and G4S security guards were responsible for the attacks.
Mr Kakas says the police are treating Mr Berati's death as homicide.
"From the autopsy report it appears that the Iranian actually died from multiple injuries sustained to the skull and that's consistent with the use of a heavy object. There were no other wounds found on any other part of the body."
Dominic Kakas says the investigation still has a long way to go with many more interviews to be carried out.
