PNG police angered by Manus report

A report into a riot at Australia's Manus island detention centre has angered Papua New Guinea police investigating the death of asylum seeker Reza Berati.

A request by PNG police to involve Australia Federal Police in the investigation was accepted by officers on the ground, but later rejected by Canberra, PNG police say.

"We were frustrated by the lack of co-operation by the Australian government, the security service provider G4S and asylum seekers," a PNG police spokesman said.

"They have been frustrating our efforts and have been since day one.

"We can't even interview suspects. They flew them to Australia, then back again without telling us."

Australia has federal police stationed in PNG as part of an extended training and community policing program.

PNG police investigating the February 18 death of Mr Berati suspect three G4S guards, two local PNG men and an expat.

The Cornell report, released in Australia on Wednesday, points the finger at a PNG Salvation army officer for the murder of Mr Berati, whose head was crushed by a rock during the riots.

The police spokesman conceded local investigators have yet to conclude if PNG police entered the camp, but says the PNG courts cannot rely on the Cornell report.

"It's a private investigation, as far as we're concerned," the spokesman said, referring to the report.

The spokesman said an official statement from the PNG police leadership will be released on Wednesday evening.

Mr Bowles later said the bill for PNG legal fees was in the order of $350,000 to $370,000.