Bougainville's retiring president says some candidates are bullying or offering inducements to buy their way into the new parliament.
John Momis first raised his concerns while speaking during Papua New Guinea's 45th anniversary celebrations on Wednesday.
Momis praised the success of PNG's Constitution, and contrasted this with the way some in Bougainville were flouting the Bougainville constitution.
He said these people were not respecting the rule of law which is the essence of democracy.
Momis said some candidates have used a variety of tactics, including money inducements, to frighten people into submission.
"Because, I guess, because we have a very weak police, rule of law is a very real problem in Bougainville."
"Especially this year when you don't have international observers here for the elections, it's quite clear that some people were more or less forcing people to vote for them, or using all types of propaganda to get people, to scare them into submission," he said.
Momis, who is due to finish his 10 years as Bougainville's president in the coming week, said some parties, including his own, were preparing demands for vote recounts.
The election count was this week extended by nine days with the Electoral Commissioner, George Manu, saying there were about 30 percent more voters and candidates than in the last poll.
Manu hoped to finish the count on Tuesday or Wednesday, with the writs to be returned to the Speaker on 24 September.