Photo: Supplied/ FB -Autonomous Bougainville Government
Bougainville's incumbent President - Ishmael Toroama - looks set to stay after initial results show him way ahead in the polls.
Toroama is leading the presidential race with nearly 90,000 votes after a primary count, the office of the electoral commission has confirmed.
"He is well ahead in terms of the votes he has collected across all three regions on Bougainville, the electoral commissioner, Desmond Tsianai told RNZ Pacific.
"Joe Lera (a longtime Papua New Guinea MP in the national parliament) is next, trailing behind with just 17,197 votes at this point," he said.
However Tsianai said "quality checks" would be carried out on ballot papers from the north, central and south regions, which could take a further three days.
Checks involved combing through the paperwork to identify if there were any discrepancies in the primary count.
"After completing those checks we should be able to calculate the absolute majority and then we will be able to anounce the final results," he said.
The one-day election in the autonomous Papua New Guinea region has been plagued by logistical problems and delays.
The election was initially planned for 4 September but was postponed a day to allow enough time to dispatch ballot papers.
Voters went to the polls the next day, then voting extended through to 6 September in some areas to ensure all eligible voters had the opportunity to cast their ballots.
There are more than 239,000 registered voters in the autonomous Papua New Guinea region, where independence remains a key issue.
Counting began three days later than expected, on 12 September; and the deadline for the return of writs has been put forward to 6 October.
Tsianai estimated that around half of the seats had been declared as of Wednesday.
Previously he said there were 33 single-member constituencies, and another five were approved last year. That makes 38 single-member constituencies, plus three regional seats for women and ex-combatants and the presidential seat, for a total of 45 seats in the parliament.
Results have been coming through on the Autonomous Bougainville Government's social media.
