The Iranian embassy in Canberra is investigating claims an asylum seeker on Manus Island is being forcibly returned to Tehran on Friday.

The Iranian man was due to fly out from Port Moresby at 11am (AEST), detention centre sources said.

Australia and Iran are in negotiations over the involuntary return of Iranian asylum seekers.

A spokeswoman for the immigration department told AAP the deportation of asylum seekers whose refugee claims have been rejected was a matter for the Papua New Guinea government.