An Iranian court on Monday confirmed the death sentences for four people convicted of participating in a $2.6 billion embezzlement scheme, the biggest fraud in Iran’s history. The four bankers and businessmen, including Mahafarid Amirkhosravi, the chief executive of the Arya Investment Group, were convicted of “disturbing the country’s economic system through collusion and corruption in the banking network.” They cannot appeal the court’s decision. Twenty-five other people, including two government officials, have been sentenced to long prison terms and large fines, the spokesman of Iran’s judiciary announced Monday.