Thomas Erdbrink has not been active on Twitter since February.

:: Concern over the fate of The New York Times bureau chief in Tehran, Thomas Erdbrink, has continued after months of him not contributing to the publication or posting to his Twitter account, with some questioning his safety.

News Agency got in touch with The New York Times enquiring about Erdbrink’s safety, following which the newspaper issued a statement.

Erdbrink, a Netherlands citizen, has reported for The New York Times from Iran since 2012 and is a resident of Tehran. However, he has been unable to work since late February, when his press credential was revoked, according to the statement.

“The authorities in Iran have barred the Tehran-based correspondent for The New York Times from working for the past four months,” the daily said in the statement.

In the statement, The New York Times international editor, Michael Slackman, said: “Officials of Iran’s Foreign Ministry have repeatedly assured The Times that Mr. Erdbrink’s credential would soon be restored but have offered no explanation for the delays or for why it was revoked.”

Erdbrink has not been active on Twitter since February after the newspaper published an article he wrote titled “The Iran Revolution at 40: From Theocracy to ‘Normality.” He was of the few Western reporters working for US media from Iran.

Some took to Twitter to raise concerns about Erdbrink’s whereabouts, as he has not been active on social media for months and has not published any articles.

Alireza Nader, the founder and CEO of New Iran, a nonprofit and nonpartisan advocacy organization in Washington, said: “Thomas Erdbrink of The New York Times has gone quiet since publishing this article [about the Iran Revolution]. And his Twitter feed stopped at this time. For better or worse, his reporting from Iran has an impact in the US. Why has he been silent?”

The timing is significant as his “disappearance” happened soon after he wrote the article on the 40th anniversary of the Islamic Revolution.

Amir Etemadi, chair and co-founder of Iranian Liberal Graduates and a member of Iran Revival, tweeted:

“Why The New York Times doesn’t say anything about its Tehran bureau’s chief Thomas Erdbrink’s situation? Why the outlet doesn’t tell you that the regime took away Thomas’ press pass after his piece for the 40th anniversary of the Islamic Revolution, and he is banned from traveling outside?”

According to The New York Times, Mr. Erdbrink’s wife, Newsha Tavakolian, who is an Iranian citizen and award-winning photographer, has also been denied permission to work.

According to a New York Times article on the matter, “it is not unusual for governments to suspend or invalidate the credentials of foreign correspondents.”

The article continues to say that the former Washington Post correspondent, Jason Rezaian, an American citizen, “was imprisoned for 544 days by the Iranian authorities for what the newspaper called absurd accusations of espionage.”