Ten days after Indonesia held the world's biggest single-day elections, more than 270 election staff have died, mostly of fatigue-related illnesses, an official says.

Key points: Almost 193 million voters were eligible to participate in the 2019 polls

Almost 193 million voters were eligible to participate in the 2019 polls Presidential, national and regional parliamentary ballots were combined

Presidential, national and regional parliamentary ballots were combined The Finance Ministry is devising compensation packages for relatives of the deceased

The April 17 elections were the first time the country of 260 million people combined the presidential vote with national and regional parliamentary polls, with the aim of cutting costs.

Voting was largely peaceful and was estimated to have drawn 80 per cent of the total 193 million voters, who each had to punch up to five ballot papers at one of more than 800,000 polling stations.

But conducting the eight-hour vote in the archipelago that stretches more than 5,000 kilometres from its western to eastern tips proved to be both a Herculean logistical feat and deadly for officials, who had to count ballot papers by hand.

As of Saturday night, 272 election officials had died, mostly from overwork-related illnesses, while 1,878 others had fallen ill, Arief Priyo Susanto, spokesperson of the General Elections Commission (KPU), said.

The Health Ministry issued a circular letter on April 23 urging health facilities to care for sick election staff, and the Finance Ministry is working on compensation for families of those who had died, Mr Susanto added.

Electoral staff were required to work under all environmental conditions on election day. ( AP: Kusumadireza )

KPU under fire as Widodo's win challenged

The KPU has come under fire over the deaths.

"The KPU is not prudent in managing the workload of staff," news website Kumparan.com quoted Ahmad Muzani, the deputy chair of the campaign of opposition presidential candidate Prabowo Subianto.

Mr Prabowo, who independent pollsters said was the loser of the 2019 polls based on quick counts, had alleged widespread cheating, and his campaign team claimed some officials punched ballots in favour of incumbent President Joko Widodo.

In 2014, the candidate challenged the legitimacy of election results in the Indonesian Constitutional Court, but it was was unanimously defeated.

Mr Widodo's security minister said the latest allegations were baseless.

Both candidates have declared victory, though quick counts suggested Widodo won the election by around 9-10 percentage points.

The KPU will conclude vote counting and announce winners of the presidential and parliamentary elections on May 22.

ABC/Reuters