The BBC says an Iranian court has issued an order that "appears to effectively freeze" the assets of 152 people associated with its Persian-language service.
"We deplore what appears to be a targeted attack on BBC Persian staff, former staff, and some contributors," said BBC World Service Director Francesca Unsworth in a statement on August 15.
Unsworth said the order, issued by a court at Tehran's Evin prison, was preventing staff from "selling or buying property, cars, and other goods."
Iran's judiciary has given no explanation for the order, the British broadcaster said.
The BBC Persian-language service, which broadcasts on television, on radio and online, is banned in Iran.
BBC Persian staff and their families "routinely face harassment" from the country's authorities, the BBC said.
Unsworth called on the Iranian authorities to reverse the court order and allow BBC staff and former staff to "enjoy the same financial rights as their fellow citizens."
The acting head of BBC Persian, Amir Azimi, said that, despite the order, journalists working for the Persian-language service will "continue to bring independent, impartial and trusted news to Persian speakers around the world."