Senior election officials in Papua New Guinea's capital were detained by police for potential corruption just hours after Tuesday's polling was deferred.
But the Electoral Commissioner Patilas Gamato has denied allegations that one of his officers was involved in suspected bribery.
The elections manager of the National Capital District, Terrence Hetinu, was interrogated at Boroko police station on Tuesday afternoon after he was found with cash and a signed document from an unnamed candidate.
The police commander, Sylvester Kalaut, told a news conference that Mr Hetinu had US$57,000 in his official vehicle.
However, Mr Gamato said the cash was meant to be payment for polling officials in the district.
Unpaid allowances was the reason the Commission gave earlier on Tuesday for deferring polling to Friday in all three of the district's open electorates and its provincial electorate.
It had said allowances were not paid in cash, but Mr Gamato said the official was compelled to carry the money because the urgent situation around the polling officers' demands warranted it.
RNZ Pacific's correspondent, Rose Amos, who was at the news conference, said Mr Kalaut also confirmed another bout of arrests earlier on Tuesday, after officials were found smuggling ballot papers out of the provincial elections office.
One of those officials was the assistant returning officer for the National Capital District, Roselyn Tobogani.
Ms Amos said 16 election officials were in police custody on Tuesday afternoon.
"One of the officials arrested is Mr Hetinu's assistant election manager," Ms Amos said. "Currently they are questioning and investigating these incidents."
The deferral of polling in Port Moresby came amid complaints about persistent problems with the electoral roll and changes to the polling schedule.
Polling began on Saturday with various provinces scheduled for polling at different stages across a two-week period.
However, the failure to conduct scheduled polling in three Highlands provinces on Monday suggested the Electoral Commission was under pressure, and on Tuesday a group of candidates petitioned the Commissioner to resign.
One of the candidates, the former prime minister Sir Mekere Morauta, urged Mr Gamato to take responsibility for the chaos.
As news broke of Mr Hetinu's arrest, Sir Mekere told a news conference the election was being rigged.
"We now have caught electoral officers with loads of money and boxes in Moresby already and this an example of what is planned to happen," he said. "As Moresby candidates, we have petitioned the commissioner to stand down."