A friend of a New Zealander who died in an Australian detention centre says authorities are trying to cover up the real cause of his death.
Rob Peihopa, 42, was found unconscious by staff at the Villawood Detention Centre in Sydney on Monday night.
His friend, also a detainee, said he suspected Mr Peihopa had died after being beaten up, but authorities were trying to whitewash it.
RNZ News agreed not to name the detainee, who has been in Villawood for the entire 10 months or so Mr Peihopa was there.
Australian Department of Immigration said Mr Peihopa was found unconscious and was suspected to have suffered a heart attack.
One said police were questioning detainees all day yesterday, because they suspected foul play.
"The word is in here, mate, is that it's suspicious. So they're treating it as a suspicious death.
"They said that he died of a heart attack in the gym. The gym was closed at that time, he was 400 metres away from the gym."
The detainee said his friend's body was found in a blind spot away from closed circuit TV cameras.
Mr Peihopa's widow called him, crying, asking for the truth, he said.
"She's shocked. Mate, she can't believe that these people are telling her that her husband died of a heart attack in the gym.
"They've already taken away his freedom, they've deprived his family of their father and now Rob's died and they're still depriving them from the truth - that's wrong, that's wrong."
Serco, which runs the detention centre, and the Australian Immigration Department refused to be interviewed.
The New South Wales coroner has begun investigations.
Greg Barnes of the Australian Lawyers Alliance said Mr Peihopa's family needed to call for a wide-ranging inquiry.
It was an unresolved question whether detainees were getting adequate medical care, and whether detention centres know enough about their medical histories, Mr Barnes said.
"This is not the first death in detention and the coroner needs to determine not only the cause of death, but the sorts of procedures in detention ... which could have alleviated this man's death.
"This man's family and the Australian community need to know how he died and whether or not it could have been prevented."