A public row over a court case has broken out between two of Iran's most powerful bodies - the hardline judiciary and the largely reformist intelligence ministry.
By Jim Muir
BBC Tehran correspondent
The ministry has accused the judiciary of overlooking crucial evidence in Tuesday's court case in which one of the ministry's officials is charged with of causing the death in custody of an Iranian-Canadian photojournalist.
Kazemi died after being arrested in Tehran
Both sides have accused one another of staging a cover-up to divert responsibility for the death of the journalist, Zahra Kazemi.
She died in early July after receiving a blow to the head following her arrest for taking photographs outside a Tehran prison.
The lengthy indictment read out in court on Tuesday morning included the accusation that the intelligence ministry took various actions to try to cover up the alleged role of one of its interrogators, Reza Ahmadi.
He alone is in the dock, accused of the semi-intentional killing of Zahra Kazemi by dealing her a single, ultimately fatal blow.
Now the intelligence ministry has hit back.
It issued a statement saying the indictment ignored what it called "the important fact" that Kazemi had written a statement on her second day in captivity, complaining that she had been beaten and thrown to the ground on the first day, when she was in the custody of judiciary officials.
The statement said the intelligence ministry would hold a news conference soon to lay the facts before the public.
The court indictment did mention statements from witnesses saying Kazemi had been hit shortly after her arrest but it said those statements had been withdrawn.
After hearing the indictment and a plea of not guilty from the defendant, the court adjourned to allow the defence time to prepare.
The dispute between two of Iran's most powerful and feared bodies is closely bound up with the intensifying power struggle between reformists, who nowadays more or less control the intelligence ministry, and hard-liners, for whom the judiciary is one of the most entrenched bastions.
Zahra Kazemi's case has already become something of a cause celebre in Iran, sparking a presidential inquiry.
The case also caused Canada to withdraw its ambassador at the way it was being handled, including the burial of Mrs Kazemi's body in Iran against the wishes of her son, who is in Canada.
The ambassador has now returned and was allowed to attend the trial.