The New York Times says that authorities in Iran have barred the newspaper's Tehran-based correspondent from working for the past four months.
The correspondent, Thomas Erdbrink, is a citizen of the Netherlands and has reported for The New York Times from Iran since 2012.
Although Erdbrink resides in Tehran, he has been unable to work since late February, when his press credentials were revoked, the paper reported.
The newspaper said it decided to make the issue public after recent speculation and comments on social media.
Erdbrink's absence from news reporting has become increasingly conspicuous amid escalating tensions between Tehran and the United States.
The newspaper said officials from Iran's Foreign Ministry had repeatedly assured it that Erdbrink's credentials would soon be restored.
Michael Slackman, the newspaper's international editor, said the ministry had not offered any explanation for the delays or provided any justification for revoking his credentials.
