The Australian Foreign Minister has asked the Papua New Guinea government to explain why an Australian journalist was deported.
The media advisor to the PNG Sustainable Development Programme, Mark Davis, was arrested by heavily-armed police last week and put on a plane to Brisbane with none of his belongings.
Julie Bishop has told the Murdoch press she is concerned and has requested more information.
She says the PNG authorities did not give Mr Davis an opportunity to contact the Australian High Commission.
The chairman of the SDP and a former prime minister, Sir Mekere Morauta, says Mr Davis was deported for political reasons after facilitating SDP press releases critical of the government's takeover of the SDP fund.
"Police kidnapped him, drove him for a few hours, with police sitting side by side with heavy guns and drive him straight to the airport, to the aeroplane. Not to the customs, not the immigration, not through anything. And that led me to describe Papua New Guinea as a country not dissimilar to Zimbabwe."
Sir Mekere Morauta.