Three soldiers are being held in custody in Papua New Guinea after they were allegedly hired by an election candidate in New Ireland province.
The warrant officer and two corporals were arrested along with 19 former soldiers when their flight landed in Kokopo on Sunday.
The police had received a tip off about suspicious passengers and cargo on the flight.
The Post Courier reported that the police found posters for the Namatanai candidate Walter Schnaubelt on the soldiers, as well as common rolls and tally sheets.
The provincial electoral manager, Joap Voivoi, said the rolls should only have been in the possession of Electoral Commission staff.
The 19 ex-servicemen were confirmed to be on their way to Namatanai to be election scrutineers.
Police were instructed not to release the three soldiers until senior officers arrived in Kokopo.