Detainee beaten by Salvation Army man

A Salvation Army worker initiated the "brutal beating" that killed Iranian asylum seeker Reza Berati inside the Manus Island detention camp, the damning official report into riots in February has found.

The employee, a Papua New Guinea national, hit Mr Berati from behind with a big stick, while PNG security guards then kicked his head as he fell down a stairway before one dropped a rock on his skull, a witness said.

Immigration Minister Scott Morrison said the incidents on the nights of February 16 and 17 were "terrible, tragic and distressing", but added bloodshed had been anticipated for months.

"There would have been no incident that night had there been no protests . . . but the protests in no way could ever justify what happened to Mr Berati," he said.

Mr Morrison said guaranteeing the safety of detainees was an "aspiration" for the Government and the report's 13 recommendations had been accepted.

The independent report, conducted by former Attorney-General Department head Robert Cornall, found tensions had been brewing for weeks as detainees grew angry and anxious over being sent to PNG with no prospect of resettlement in Australia.

Mr Cornall found those feelings had been aggravated by antagonism between detainees and PNG nationals, with some asylum seekers accused of racism.

The report found there had been warnings to the Australian Government to bolster security but nothing was done despite the swelling number of detainees. Extra security guards had been deployed to the centre.

Security contractor G4S' intell- igence assessment for February 12 reported detainees would attack staff four days later and that a police response of "lethal force" would not worry them.

Mr Cornall said only 400 of the 1340 detainees took part in the protests, with the flashpoint a meeting on February 16 that left some asylum seekers dissatisfied with answers given about their processing.

That night, detainees began rioting. PNG nationals, led by G4S guards, charged the centre armed with sticks, pipes and stones in response.

One man was lucky to survive after his throat was cut.

The next night, masked detainees carried clubs and stones as they tore fences down while Iranians taunted locals with racist chants and exposed their genitals.

The PNG Police Mobile Squad, local and some expatriate G4S guards and villagers retaliated by storming the camp and bashing detainees.

Police also fired their guns.

A detainee said Mr Berati, 23, had been in the internet room when gunshots were fired and he climbed the stairs to go to his room.

The witness said the Salvation Army worker, whose name was redacted in the report, followed Mr Berati and hit him twice before more than 10 guards kicked him and dropped the rock on his head, fracturing his skull.

In a statement, the Salvation Army said it would be inappropriate while police were still investigating to comment on the claim its employee had led the assault on Mr Berati.