IRAQI security forces captured Abu Musab al-Zarqawi, the fugitive terrorist leader, last year but freed him because they did not know who he was.

According to Major-General Hussein Kamal, the Deputy Interior Minister responsible for Intelligence, the head of al-Qaeda in Iraq was detained by police for several hours more than a year ago in Fallujah, which was then an insurgent stronghold.

“They caught him and held him but they did not know who he was, so he was allowed to go free,” General Kamal told The Times yesterday.

The mistake emerged a year ago after the capture and interrogation of Ahmed Abdullah al-Shayea, a Saudi suicide bomber who survived the explosion of a fuel tanker.

The US Government has offered a reward of $25 million (£14.1 million) for al-Zarqawi, who has claimed responsibility for some of the deadliest attacks in Iraq over the past 2½ years. He is known to be a master of disguise. In April he eluded capture after he was apparently injured by US forces, who have teams tracking him. There are fears that the relative peace of the elections, during which insurgents observed an unofficial ceasefire, will be shattered by renewed violence. Election officials said that about 70 per cent of the country’s 15.5 million voters had cast their ballots in parliamentary elections on Thursday.

Preliminary results may be available soon, but a final tally is not expected for at least two weeks. Unofficial trends are emerging. The main Shia party is expected to win the most seats in the 275-member parliament, with huge support from the Shia heartland in southern Iraq.

The Kurdish alliance will dominate northern provinces, and Sunni candidates, who boycotted the previous election, are expected to do well in the central and western provinces. A secular nationalist party led by Ayad Allawi, the former Prime Minister, is likely to attract support among middle-class voters in the main cities, Baghdad, Basra and Mosul.

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