A billionaire businessman that was responsible for the biggest bank fraud Iran has ever seen has been executed, Iranian state media has said.

Mahafarid Amir-Khosravi, also known as Mansour Aria, was hanged at Tehran’s Evin prison on Saturday after being convicted of a scam that was said to have cost Iranian banks nearly £1.5 bn.

Alongside Khosravi, 39 defendants were convicted for fraud, with four others being sentenced to death.

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According to Khosravi’s lawyers, the execution had taken place in secret and without their knowledge.

Gholam Ali Riahi, Khosravi's lawyer told Iranian news website khabaronline.ir that “he had not been informed of the execution,” and that Khosravi’s assets were at the “disposal of the prosecutor’s office.”

The crimes that led to Khosravi’s death related to a massive campaign of fraud that had started in 2007.

The fraud involved Khosravi forging documents to get credit from Iran’s biggest bank, Bank Saderat.

Khosravi used the credit to purchase state-owned assets including Iran’s major steel producer Khuzestan Steel Co.

Khosravi also used the money to buy 35 other companies, which included a mineral water producer, a meat importer and a football team.

The trial has raised questions about the level of corruption in the state-regulated economy of Iran.

Many believe that during the administration of President Mahmoud Ahmadinejad corruption was rife throughout those that controlled the country’s economy.

The government denied any involvement with the actions of Khosravi.