Amir Paivar, a business reporter at BBC Persian, said that as a result of the tightened trade sanctions, Iran’s income from oil exports had fallen by 45% this year, causing the shortage in dollars and other hard currencies.

He added that Iranian authorities had for many years used the country’s abundant oil earnings to keep the rial artificially high.

With oil revenues now sharply reduced, our reporter said that both the government and the central bank now seemed unsure how to react.

He added: “Iran’s years of state intervention in the artificial appreciation of the rial, thanks to abundant petro-dollars, has turned the currency into a barrel of gunpowder now detonated by sanctions.