Saying officials have undertaken yet another campaign of "bullying and harassment" of its Persian service staff, the BBC called on the Iranian government to "repudiate the action of its officials."
In a blog post, the BBC's Director General Mark Thompson also called on the international community to "put maximum pressure on Iran to desist in this campaign of intimidation, persistent censorship and a disturbing abuse of power."
According to Thompson, over the past couple of months Iran has targeted its Persian service employees by threatening family members who live in Iran. Thompson writes:
"In recent months a number of relatives of members of BBC Persian staff have been detained for short periods of time by the Iranian authorities and urged to get their relatives in London to either stop working for the BBC, or to 'co-operate' with Iranian intelligence officials.
"In other instances, passports of family members have been confiscated, preventing them from leaving Iran. This has left many BBC Persian staff too afraid to return to the country, even to visit sick or elderly relatives. Some have had their Facebook and email accounts hacked."
Thompson believes Iran is doing this because of the BBC's "impartial and balanced coverage of events in Iran and the wider region."
In the past, Thompson notes, Iran has jammed the signal of BBC Persian TV.