MALE, Maldives: Voters across the Maldives came out in force Saturday to vote in an election that could see the honeymoon islands' first elected leader return to power, a year after being toppled.

Long queues formed outside polling booths before voting started under bright sunshine across the Indian Ocean archipelago, with the incumbent President Mohamed Waheed among the first to vote.

Waheed came to power in February 2012 when the first democratically elected president, Mohamed Nasheed, was forced from office following a mutiny by the security forces that he branded a “coup”.

Nasheed, a British-educated scuba-diving fanatic who once held a cabinet meeting under water, is contesting again and is seen as the clear frontrunner among the four candidates.

Waheed is also standing — along with tourism tycoon Gasim Ibrahim and Abdulla Yameen, the half-brother of long-time Maldivian autocrat Maumoon Abdul Gayoom.

“The preparations went well and everything will be fine,” Waheed told journalists after casting his vote on the main island, Male.

“I think voters are coming out early.”

Yameen, who is seen as the main challenger to Nasheed, called it a “watershed election” after voting near the university.

“Things have gone so wrong the last four-five years. It is absolutely imperative that we change for the better this time,” he said.

If none of the candidates scores more than 50 per cent on Saturday, a second round run-off is scheduled for September 28.

Voting is taking place at polling stations on all inhabited islands as well as on the tourist resorts that have made the country famous as a “paradise” destination.

Nearly one million holidaymakers visited the Maldives last year, drawn to its secluded beaches on private coral-fringed islands where cabins can cost several thousand dollars a night.

Any more instability would spell problems for the industry, the lifeblood of the country, which suffered a wave of cancellations following the unrest last year.

Nasheed resigned from office on national television, which had been taken over by the security forces, whom he said threatened him and his family with violence unless he stepped down.

Waheed, who was then vice-president, took the oath immediately afterwards, leading Nasheed to accuse him of taking part in a conspiracy with former dictator Gayoom, who ruled for three decades until 2008.

Waheed denies the charges, but the contested change in leadership was a blemish on what was a flourishing democracy in South Asia and has left a legacy of bitterness and distrust.

“We are apprehensive that renegade elements within the police and military...might intervene during voting or during counting,” Nasheed told a press conference on Thursday.

His social programs and activism to highlight the danger of climate change — 80 per cent of Maldivian land is less than one metre above sea level — earned him plaudits at home and abroad, but he was not universally popular.

After growing frustrated with the judiciary, he sent the army to arrest the head of the country's criminal court, which led to a pending criminal charge that he abused his powers while in office.

His work to increase taxes and introduce budget guesthouses earned him enemies among the powerful tourist tycoons, while he is seen by some as being too eager to please neighbouring India.

If he fails to secure a majority in the first round, the 46-year-old is likely to see his three opponents join forces to try to defeat him in the run-off.

Lawrence Gonzi, a former prime minister of Malta who is heading an observer mission to the election from Commonwealth countries, said campaigning had gone smoothly for Saturday's vote.

The results are expected around midnight.

UN Secretary General Ban Ki-moon urged the country last week to “ensure that the upcoming presidential elections...will be conducted in a credible and peaceful manner”.