Hamid Karzai is poised for outright victory in Afghanistan's bitterly contested presidential election after officials said he had won more than 50 per cent of the vote.

But his likely re-election without having to face a second round after reaching the milestone with almost all of the votes counted was mired in controversy. United Nations monitors said they had found "clear and convincing evidence" of fraud and election officials ordered a recount of thousands of disputed ballot papers.

He passed the key 50 per cent mark as international concerns that the election was being stolen by massive ballot-rigging reached a crescendo. In a day of rapid developments, the country's fragile democratic process was placed in further doubt when an election watchdog ordered officials to recount an unknown number of ballot boxes that appeared blatantly rigged.

The Election Complaints Commission (ECC) said it had found evidence of cheating in polling stations where vastly higher than expected numbers of votes had been cast.

The United Nations, United States and European Union all joined in the condemnation of the fraud as the international community belatedly decided to speak out on what Dr Abdullah has alleged is "state-engineered" rigging.