A group of West Papuan independence activists has been flown to Papua New Guinea after arriving in Australian territory seeking asylum.

The group's spokesman told the ABC they were initially told they would be flown to the Australian mainland.

However, as soon as the doors on the plane were closed, Immigration officials told them they were heading to PNG.

Mr Yacob Mandabayan, a member of the West Papua National Authority, says the group requested asylum in Australia.

He says they feared persecution by Indonesian authorities because they had held a symbolic ceremony showing solidarity with the Freedom Flotilla that had left Australia some time ago to raise awareness of the plight of West Papuans.

Mr Mandabayan and four other men, a woman and a 10-year-old boy left Papua several days ago and crossed the border into PNG.

ABC's PNG correspondent Liam Fox says they made their way down to Boigu Island with the help of local fishermen and were met by Australian officials in the Torres Strait.

After several days of interviews, they were taken to Horn Island in the Torres Strait before being asked to board a plane on Thursday night.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 5 minutes 15 seconds 5 m Asylum-seekers claim they were duped ( Liam Fox ) Download 2.4 MB

They say that before getting on the plane they were told that they would be taken to the Australian mainland, but Mr Mandabayan says once they were on the plane the story changed.

"When we are on the aircraft, when the door is closed, the guy from the Immigration tell us that we are not going to the mainland but we are returning to PNG," Mr Mandabayan said.

"I am asking them why, but their answer because that's what their boss or the head office or anything like that say that because that's what their country decide.

"We are so sad and it's driving us crazy and we all cry. That's upsetting," he said.

Fox says the group was greeted by officials from the International Organisation for Migration (IOM) and were taken to the Hideaway Hotel on the outskirts of Port Moresby.

They remain opposed to being sent back to PNG because they believe that some of the many Indonesians in the country could be spies.

"They're even fearful that they could be kidnapped and taken back across the border, but mainly the proximity to Indonesia is what they fear," Fox said.

"If what these West Papuans say is correct, this is a completely new way of dealing with asylum seekers.

"In the immediate past they have been sent to either Manus Island or Nauru, to the processing centres there. This has not happened in this case."

Immigration Minister Scott Morrison is in PNG on an official visit but he or his office have not commented.