International election observers have said problems with the electoral roll in Papua New Guinea that prevented thousands of people from voting are "widespread".
In its interim statement, the Commonwealth Observer Group called for an urgent review after the election to improve the accuracy of the roll.
Elections are in their third week and while polling continues in a small number of areas, the counting of ballots has started in others.
Thousands of people were prevented from voting because their names were not on the electoral roll, despite saying they had registered.
The Commonwealth Observer Group sent teams to 12 provinces to monitor the polling.
The group's chairman, Sir Anand Satyanand, said his observers found the problem was "widespread".
"The group was very disappointed to note that previous Commonwealth Observation Group reports that highlighted the need to address this issue of the common roll have yet to be implemented," he said.
On polling day, the observers said most booths opened late, the distribution of ballot materials was not completed on time and some booths were given fewer ballot papers than the expected number of voters.
Sir Anand said the logistical problems and the inaccuracy of the roll highlighted the need for adequate and reliable funding for the Electoral Commission.
The observers also found problems that affected previous elections — including vote buying, or 'money politics' — were again apparent.
Sir Anand said state resources and provincial and district development funds were used to buy voter support or to pay for projects designed to induce voters.
He said the group was advised money politics had "significantly influenced" the electoral process.
Despite these and other problems, such as incidents of election-related violence, Sir Anand and the observers said the election results would likely reflect the wishes of the voters.
"Of course there are things that could have been done in a better or a different way," he said.
"But as I said at the outset, delivering a completely satisfying election in a country like this is a work in progress."
Electoral Advisory Committee resigns
Sir Anand would not be drawn to comment on the resignation of PNG's Electoral Advisory Committee (EAC).
All three members of the committee resigned on Sunday, saying the Electoral Commission refused to provide them with basic information to allow them to monitor the conduct of the elections.
Member Richard Kassman said with problems emerging such as the accuracy of the common roll, their position was becoming increasingly untenable.
"People, and media on behalf of the people, are well justified in saying the EAC is deaf, blind and dumb, and we are very concerned about our integrity in that regard," Mr Kassman said.
"We're hearing what you're hearing as well, and we feel it was incumbent on us to do our job, and this is why we've come so far to this point where we are now."
