An Iranian newspaper says the country's Central Bank has officially banned the use of cryptocurrencies in financial transactions in order to "prevent crimes such as money laundering and terrorism."
The move is seen as part of Tehran's efforts to control the currency market after the Iranian rial hit an all-time low earlier this month.
Monday's report by the Donya-e Eqtesad daily says the ban applies to "all monetary and financial centres of the country," including banks, financial institutes and currency exchange offices.
Though cryptocurrencies, such as bitcoin, have never been authorised in Iran, they were available in parallel markets.
Cryptocurrencies are created and exchanged independent of banks or governments. Transactions are typically anonymous but the currency can be converted into cash when deposited into accounts at prices set in online trading.