Afghanistan's opposition leader has called for a criminal investigation into allegations of massive vote rigging in last month's elections — and accused his rival, President Hamid Karzai, of treason in an exclusive interview with The Times.

Abdullah Abdullah, the country's former foreign minister, charged Mr Karzai with "state-engineered fraud" in the August 20 polls. "It's worse than a crime, it's treason," he said, adding that Mr Karzai "doesn't think about the country, he thinks only of himself. He has been caught red-handed."

Mr Abdullah is trailing Mr Karzai in partial results published by the Independent Elections Commission (IEC), an organisation that he claims is under the control of the President's supporters. A UN-backed elections watchdog ordered the IEC to begin a massive recount of votes last week, saying that it had unearthed "clear and convincing evidence of fraud".

Although Mr Karzai narrowly passed the 50 per cent threshold that would allow him to avoid a run-off, the recount could push his support back below that level, meaning that the country might have to vote for a second time.

The IEC has given warning that the process could take months, by which time Afghanistan's harsh winter will have set in, possibly precluding another vote until the spring. The process could leave the country rudderless for months at a time when the Taleban is re-emerging as a dangerous force. Both sides have rejected international calls for a unity government.

"What's at stake is Afghanistan, the future of this country," said Mr Abdullah. "The country will die because of this sort of thing. Fraud is the extension of this corruption which prevailed in this system."

Click here to read more on this story from the Times of London.