Press freedom campaigning body Reporters Without Borders has condemned the arrest of the entire staff of Iranian presidential candidate Mir-Hossein Mousavi's newspaper, Kalemeh Sabz, as pressure on domestic journalists reporting the ongoing protests has intensified this week.

Iranian authorities arrested 25 journalists and other staff at the newspaper owned by Mousavi earlier this week. RSF said that in total about 40 journalists in Iran had been arrested since 12 June and remained behind bars.

The Foreign Office has also confirmed it was aware of the case of one of the detained journalists with joint British and Greek nationality who was held in the crackdown at the end of last week.

Iason Athanasiadis-Fowden, known as Jason Fowden, a Washington Times reporter, was arrested as he was attempting to leave the country, according to the Iranian news agency IRNA.

RSF, the Paris-based journalists' charity, reported that Kalemeh Sabz's editor, Alireza Behshtipour Shirazi, confirmed the arrest of his whole staff on German radio.

Kalemeh Sabz ceased publication on 13 June but was due to restart on 23 June. However, the prior evening, agents from Tehran's prosecutor's office surrounded the building where the paper is based.

Earlier this week, 180 Iranian journalists wrote an open letter to Iran's leaders, protesting the "deplorable and critical" state of Iran's media.

Yesterday, foreign secretary David Miliband confirmed that the British embassy was in touch with the Iranian authorities about Athanasiadis-Fowden, a journalist with dual British and Greek nationality who was arrested last week.

Miliband said the Greek government was taking the lead on the case as he had been travelling on a Greek passport. He added that he had not received any reports of any other Britons being taken into custody.

Earlier this week the Iranian foreign ministry accused the BBC and Voice of America of being mouthpieces of their respective governments and seeking to engineer the ongoing riots that followed the presidential election.

Another Iranian ministry also threatened to take "more stern action" against British radio and television networks if they "continued to interfere" in the country's domestic affairs.

This followed an announcement last Friday by the BBC World Service that it was attempting to combat continued broadcast interference from within Iran by increasing the number of satellites it uses to transmit its Persian television news service and extending the channel's hours.

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