Iran and six world powers (five permanent members of the UN Security Council plus Germany) struck a historic deal in July 2015 to lift most financial and trade restrictions against Tehran in return for curbs on its nuclear program. The deal, formally known as the Joint Comprehensive Plan of Action, came into force in January last year.
According to the statement, after the deal's implementation, all the frozen assets in different banks and oil debts from various countries were collected.
Under the strict economic and banking restrictions, many oil importers could not pay their bills and as months passed, the debts ballooned to the detriment of the Iranian economy, Financial Tribune reported.
Unpaid debts to Iran by international petrochemical companies and refineries had amounted to $18 billion, among which Greece, India, Shell, BP refineries and Korea Petrochemicals topped the list. However, as soon as the nuclear accord was implemented and banking restraints were removed, the Persian Gulf country began to collect its debts.
CBI adds that as a result of full access to foreign exchange resources, the domestic foreign exchange market is experiencing stable days.
"Otherwise the market would have definitely witnessed severe fluctuations," it said.
The money from European oil and gas exports ends up in CBI's accounts in the central banks of Italy, Austria and top-tier western European banks.
The bank notes that since European banks offered their services to Iran and helped with settlement processes, all trade with Europe goes through the regular banking system at a very small fee.
In Friday's second presidential debate, some candidates accused the banking system of cronyism, questioned the merits of nuclear deal and claimed that the central bank is unable to receive oil money due to banking restrictions.