Male, Nov 17 (PTI) Abdulla Yameen, half-brother of former autocratic ruler Maumoon Abdul Gayoom, today clinched an unexpected victory in the presidential run-off elections by defeating former President Mohamed Nasheed, who had led in two recent aborted polls.

The winning candidate, a 54-year economist also known as Yameen Abdul Gayoom, contested as a Progressive Party of Maldives candidate. He bagged 51.39 per cent of the votes, compared to 48.61 per cent ballots secured by Nasheed, senior government official Masood Imad told PTI.

Over 90 per cent of eligible voters exercised their franchise in the second round of the much delayed election to choose a new president amidst a constitutional crisis.

Imad said the new President would be sworn in after the announcement of official results by the Elections Commission tomorrow.

The Majlis or Maldivian Parliament has scheduled a special session on Sunday for the swearing-in ceremony.

The results are likely to end more than a year of political turmoil since 46-year-old Nasheed resigned under duress in February 2012 in a controversial transfer of power.

In the first round of elections held in September, Nasheed led over Yameen and Jumhooree Party candidate Gasim Ibrahim but failed to secure a more than 50 per cent of the votes.

But before a run-off could be held, the results were annulled by the Supreme Court which cited irregularities in the voters' list.

A second attempt to hold the polls on October 19 was thwarted by police after a Supreme Court ruling.

The re-vote finally took place on November 9 and Nasheed again comfortably led in the first round but could not cross the half-way mark, resulting in today's run-off with runner up Yameen.