LONDON: The Iranian government has intimidated and arrested relatives and friends of Persian-language journalists working abroad in a bid to silence them, Human Rights Watch said Friday.

The rights group highlighted the case of a BBC reporter Iranian authorities "arbitrarily detained and held as a hostage" for almost two weeks as Iran prepares to hold parliamentary elections on March 2.

HRW said security forces raided the home of a BBC Persian service employee's relative in Tehran in mid-January, searched and confiscated their belongings, and took them to Evin prison.

Within hours, a man claiming to be the relative's interrogator contacted the BBC employee in London, offering to free the family member in return for information about the BBC, the rights group said.

HRW said the detainee was released on bail several days ago.

"Detaining a BBC reporter's relative seems to be part of a wider campaign to harass Iranian journalists by putting pressure on them and their families," said Sarah Leah Whitson, HRW's Middle East director.

"It suggests that authorities detained the relative to silence the reporter and the BBC. It also sends a message that the government's long arm of repression can extend well beyond borders."

A BBC staff member who spoke to HRW expressed concern about the targeting of family members of journalists.

He said he and his colleagues had been exposed "to almost daily insults and personal attacks on various pro-government websites and blogs inside Iran", but added: "This is really a red line for us, and we can't stay silent."

In October, the BBC accused Iranian authorities of harassing relatives of its London-based Iranian employees.

Iran has frequently accused the BBC of fueling the unrest that broke out following the disputed re-election of President Mahmoud Ahmadinejad in 2009.