Asylum seekers and workers at the Manus Island detention centre should be flown to Australia to give their evidence to the newly established Senate inquiry, a spokesman for Papua New Guinea's Prime Minister says.

Media adviser to Prime Minister Peter O'Neill, Daniel Korimbao, said Australia should pay for detainees to fly to Canberra to give witness accounts of the fatal violence to the parliamentary committee that was passed on Wednesday.

''I doubt if the PNG government would allow the Australian Senate to conduct an inquiry on PNG soil and jurisdiction,'' Mr Korimbao said. ''The better option would be to have the detainees, and any other person, flown to Canberra, where the inquiry is being held, to be interviewed there.''

The proposal came as a Senate report slammed the Coalition's ''severe secrecy'' on immigration and operational borders. The report, handed down on Thursday, recommended that the Australian Parliament consider changing its procedures, criticising the Abbott government's ''unwillingness to engage in a meaningful way''.

Greens senator Sarah Hanson-Young, who initiated the inquiry into the Manus Island violence, said the detention centre had become a ''jurisdictional mess''.

''It is concerning that the Australian government is spending billions of dollars on a gulag in PNG and it should work to ensure that the Parliament can investigate what goes on there,'' she said.

''If the Abbott government genuinely wants to find out what really happened that night, it will do what it can to make sure the inquiry is able to visit Manus Island and take evidence from refugees and staff.''

But a spokesman for Immigration Minister Scott Morrison said it was a ''matter for the committee'' on whether asylum seekers could be flown to Australia, and who would foot the bill.

On Friday, Mr Morrison said Australia would not treat PNG as a ''colony'' with respect to the Manus Island inquiry.

''Australia just can't go around treating PNG as a colony demanding people turn up and walk around wherever they like,'' he told ABC radio.

''That's what Senator Hanson-Young and the Labor party seem to be saying.''

Refugee rights advocate Pamela Curr, from the Asylum Seeker Resource Centre, applauded the idea, saying it provided a safer option than having an inquiry on the island. ''It makes very good sense to do so,'' she said. ''From a practical point of view it places enormous pressure on PNG and the private contractors to keep the witnesses safe after they have given evidence.''

But mental health advocates disagreed, saying asylum seekers were likely to suffer enormous psychological distress.

''To give an account of what happened and then to go straight back to the very place where they have been attacked would cause strong psychological distress,'' said Professor Louise Newman, from Monash University.

The inquiry will take evidence in April, after the government's own independent inquiry has concluded, and is expected to call asylum seekers, staff from G4S - the company that has been running the centre - and the Salvation Army, Papua New Guinea police and Australian officials.

Meanwhile, on Friday, Mr Morrison also touched on a call by UN High Commissioner for Human Rights Navi Pillay for Australia to review regional resettlement arrangements following the Manus Island violence and the need to uphold human rights.

He said he was reviewing arrangements, and took credit for the government's boat policy because it had stopped asylum seeker deaths at sea.

''(Ms Pillay) was also deeply distressed by the many boat deaths. The fact that we've been able to have that success is to the government's credit.''

with AAP

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