Iran's currency hit a new low on July 29 amid a deepening economic crisis and the imminent return of U.S. sanctions that were lifted under the 2015 nuclear deal between Tehran and world powers.
The Iranian rial fell to 112,000 to the dollar on the black market exchange from 98,000 to $1 the previous day, the Associated Press news agency reported.
Meanwhile, the official exchange rate was 44,070 to the dollar, compared to 35,186 at the beginning of the year.
The drop of the rial has accelerated following the U.S. decision to pull out of the nuclear deal in May and the announcement of increased sanctions beginning next month.
The government last week replaced the country's central bank Governor Valiollah Seif, who has been sharply criticized for his handling of the currency crisis.
The United States is set to reimpose its full range of sanctions in two stages on August 6 and November 4, forcing many foreign firms to cut off business with Iran.