Air Niugini has resumed flights to Buka in northern Bougainville.
The suspension followed threats last week by a creditor of the local government which aviation news site ch-aviation reports owes around $US4.5 million.
On Friday a group made up of service providers who had reportedly not received payment owed them by the Autonomous Bougainville Government forced a plane to return to Papua New Guinea mid-flight.
Air Niugini suspended flights on Friday but a spokesperson said the service resumed on Monday.
The airline was providing flights from Port Morseby to Buka six times a week, including three flights via Rabaul/Kokopo.
Flights between Port Morseby and Bougainville's southern town of Arawa were not affected.