The defence in French Polynesia's trial of the current and the former presidents says their case should be thrown out because of the statute of limitations.
President Edouard Fritch and his predecessor Gaston Flosse are accused of abusing public funds over their actions as mayors of the town of Pirae from the late 1990s onward.
They are alleged to have arranged for the town administration to pay for the water supply to the upmarket Erima neighbourhood, where Flosse lived.
The charges followed a 2011 auditor's report which found that Flosse set up the free supply which Mr Fritch continued, with both of them billing the town.
Flosse has rejected the claims and his lawyer wants the case to be thrown out.
The two risk jail terms of up to ten years and fines in excess of $US1 million as well as a ban on them holding public office.
Today's case is Mr Fritch's first during his current term, after being convicted of corruption twice during his previous term.
In the current case, he was charged before last year's election but a first attempt to try him last year was deferred because the court was busy with the Air Moorea crash trial.
The two politicians have fallen out and in February, Flosse was fined $US20,000 for making the same defamatory statements about Mr Fritch.
Gaston Flosse has been barred from public office since 2014 because of corruption convictions.