The police in Samoa do not believe anyone else was involved in the death of a New Zealand man in a prison cell during tropical cyclone Evan.
Prison staff found 38-year-old Hans Dalton dead in four litres of water on Boxing Day morning in Apia.
Water was being kept in the cells after Cyclone Evan cut running water supplies.
The assistant police commissioner, Leaupepe Fatu Pula, says mental-health staff had transferred Mr Dalton to the police because they had nowhere to restrain him when he became violent.
Leaupepe says before he died Mr Dalton could be heard hitting his head against the walls and steel doors of his cell.
"We are treating it as a homicide but we are not looking for anyone else and we suspect the deceased cause his own death."
Leaupepe Fatu Pula says a post-mortem was done before Hans Dalton's family took his body back to New Zealand.