JAKARTA - Unofficial quick count tallies of votes cast in the Indonesian presidential election on Wednesday (April 17) have placed the incumbent Joko Widodo ahead of his rival Prabowo Subianto by between seven and 10 percentage points, according to five pollsters.

Quick counts by Jakarta-based Poltracking Indonesia gave Mr Joko - popularly known as Jokowi - the widest winning margin, with a 55.21 per cent vote share over Mr Prabowo's 44.79 per cent, while the Indikator showed the smallest victory margin of 53.91 per cent to 46.09 per cent.

The counts are based on more than 95 per cent of the ballot data targeted for sampling by pollsters.

Based on an internal survey by the Jokowi-Ma'ruf Amin team, the ticket will gain victory with a score of 57 to 58 per cent, Mr Hasto Kristiyanto, the secretary general of Indonesian Democratic Party of Struggle, told reporters in a Kompas TV broadcast.

Mr Prabowo's team, however, have claimed that their candidate is in the lead.

Campaign director Sugiono told reporters as quick count results were being released that his team had conducted their own assessments once polls opened, and their exit polls found that their Mr Prabowo and his running mate Sandiaga Uno outperformed their opponents at 5,475 polling stations in 34 provinces.

Mr Prabowo and Mr Sandiaga, he said, received 55.4 per cent of votes while Mr Joko and Dr Ma'ruf secured 42.8 per cent.

Mr Prabowo's team have over the course of the campaign raised doubts over voter rolls, claiming that 17.5 million names on the list are problematic.

On Wednesday, spokesman Dahnil Anzar Simanjuntak said the team had received several reports regarding "oddities" in the election. For instance, several polling stations in Palembang did not exist, he said.

And, he added: "There are many polling stations that opened late at 11am, when they're supposed to be open at 7am. This is an important matter that (the team) submits for evaluation."

"As the tallying process is still ongoing, we urge all witnesses to continue overseeing this process at polling stations in their respective districts. Safeguarding the votes is so important."

Quick counts conducted by private polling and survey agencies, which look at a sample of ballots after polling closes to estimate the overall vote, have largely proven to be accurate in past elections.

Additional reporting by Wahyudi Soeriaatmadja, Linda Yulisman and Jeffrey Hutton