Kazemi died of head injuries in custody

Mohammad Reza Aghdam Ahmadi was cleared of killing photographer Zahra Kazemi, who died in custody in Iran last year.

Zahra Kazemi's son, Stephan Hachemi said the trial was a "cover-up" to divert attention from the real killer.

Mr Hachemi and his supporters are urging Canada to bring Iran before the international court in The Hague.

Mrs Kazemi was arrested last June after taking pictures outside a prison in the capital, Tehran.

She died in hospital in Tehran on 10 July after falling into a coma, having received head injuries during more than three days of interrogation.

'Semi-intentional murder'

Ms Kazemi's family has previously said a high-ranking official of the justice department struck the fatal blow, and that the court was putting someone else on trial to protect the real killer.

It's a cover-up. They're not ready to implicate Iranian officials. I have only three letters - ICJ - the International Court of Justice Stephan Hachemi

Iran refused to allow Canadian diplomats to attend the closed-door hearing where Mr Ahmadi was accused of "semi-intentional murder".

The BBC's Miranda Eeles in Tehran says lawyers acting for the Kazemi family say they now have 20 days to appeal.

They are calling for the judiciary to appoint a new investigator to look into the case and for the trial to take place at a provincial court, our correspondent says.

Mr Hachemi said: "It's a cover-up. They're not ready to implicate Iranian officials. I have only three letters - ICJ - the International Court of Justice."

Blood money

The BBC's Lee Carter, in Toronto, says there has been very little official Canadian government reaction to the court ruling - it says it wants to study the verdict further.

The case soured relations between Iran and Canada and Ottawa recalled its ambassador in protest.

The case also deepened the rift between Iran's reformist government and the hardline judiciary, with both sides accusing the other of a cover-up.

Reformist President Mohammad Khatami said he believed Mr Ahmadi was innocent and called on the judiciary to identify "the real guilty person".

Irna news agency quoted a Justice Department source as saying Ms Kazemi's blood money - a sum given to the family of the victim by the murderer - will be paid for by the state treasury.

Lawyers for the family said the family would reject financial compensation if Iran offered any.