TEHRAN, Iran (AP) — An Iranian court has sentenced four people to death and given two more life sentences on charges linked to a $2.6 billion bank fraud described as the biggest financial scam in the country's history, an official said Monday.

The trial, which began in February, involved some of the country's largest financial institutions and raised uncomfortable questions about corruption at senior levels in Iran's tightly controlled economy.

But few specific details have been released, possibly to avoid exposing too much internal scandal while Iran's leaders seek to assure the country it can ride out tightening sanctions over Tehran's nuclear program.

Prosecutors have only referred to the linchpin defendant by a nickname and have provided just general information about his purported business empire. The main charges included using forged documents to get credit at one of Iran's top bank to purchase assets, including major state-owned companies.

The official IRNA news agency gave no names at all for most of the other defendants in the Revolutionary Court, which deals with cases involving security and organized crime. The report did not say when the verdicts were issued.

The report quoted state prosecutor Gholam Hossein Mohseni Ejehei as saying a total of 39 defendants received sentences, including four death sentences, two life terms and the rest of up to 25 years in prison. He said officials including deputy ministers in the government were among those sentenced, but did not identify any of them.

The main defendant, referred to by a nickname "Amir Mansour Aria," was among those charged with a potential capital offense. In February, state TV said he was accused of being "corrupt on earth," an Iranian legal term that means that the defendant is an enemy of God, and which in practice is a catch-all term for a variety of offenses. The charge carries the death penalty.

Aria pleaded not guilty, but acknowledged that he has violated some laws, the Iranian media said.

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The indictment described Aria as head of the Aria Investment Development Co. It said the owners used "incorrect connections with executive and political elements" to accrue wealth.

"Dozens of instances of bribe payments to staff and managers of banks have taken place under various titles," it said.

Ejehei said the sentences are appealable. By law the convicted have 20 days to appeal.

Meanwhile, President Mahmoud Ahmadinejad and his hardline rivals traded blows in their political power struggle. A court stripped one presidential ally of his job while officials in Ahmadinejad's government brought charges against the brother of one of his prominent critics, the speaker of parliament.

Ahmadinejad has faced more than a year of withering political attacks after challenging Supreme Leader Ayatollah Ali Khamenei over the selection of the intelligence minister. Dozens of Ahmadinejad's allies have been arrested or driven from power by backers of Khamenei, and Ahmadinejad has been left severely weakened with less than a year left in his second and final term.

Ahmadinejad was once the favored son of Iran's theocracy, but his defiance of Khamenei was considered to be a rebellion against the supremacy of the clergy and the president's conservative allies turned on him. He still retains a following among Iran's working classes and rural poor who see the ruling clerics as aloof and out of touch.

In the latest twist, a court stripped one of Ahmadinejad's top appointees of his job after claims he was linked to the deaths of anti-government protesters, the IRNA news agency said.

The ruling against Saeed Mortazavi, head of Iran's social security organization, followed a suit filed by a group of anti-Ahmadinejad lawmakers.

In 2010, a parliamentary probe found Mortazavi — then chief Tehran prosecutor — responsible for the deaths by torture of at least three anti-government protesters who were in custody. Angry lawmakers in April threatened to impeach the country's labor minister, who appointed Mortazavi, over the case.

In a separate report, IRNA said Javad Larijani — the brother of both the country's parliament speaker and its powerful judiciary chief — came under investigation over allegations he illegally took control of protected land.

Tehran's chief prosecutor Alireza Avaei was quoted as saying that a court is studying the allegations. The claims were filed by the government agency in charge of natural resources.

The Larijani family are prominent critics of Ahmadinejad.

Larijani's brother Sadegh heads the judiciary and another brother, Ali, is parliament speaker. Javad leads the judiciary's human rights council. No date has been set for a hearing.