Ahmadinejad, 48, won the backing of the religious poor to defeat veteran political heavyweight Akbar Hashemi Rafsanjani, who was supported by pro-reform parties and wealthy Iranians fearful of a hardline monopoly on power in the Islamic state.

"The figures show that Ahmadinejad is the winner," Interior Ministry spokesman Jahanbakhsh Khanjani told reporters.

He will be Iran's first non-cleric president for 24 years when he takes office in August.

An official at the Guardian Council, which must approve the election results, said that out of 24.8 million votes counted, Ahmadi-nejad had 61.7 percent, defying forecasts of a tight race.

Officials said turnout was about 26 million, or 56 percent, down from the 63 percent of Iran's 46.7 million eligible voters who cast ballots in an inconclusive first round on June 17.