Sherif Mansour, regional coordinator for the Committee to Protect Journalists, said Bahraini freelance correspondent Mohamed Hassan allegedly was detained by masked security officials this week. The organization said authorities "have harassed and detained" him repeatedly since early last year.
Bahraini authorities this week passed legislation meant to crack down on terrorism in the country. Measures were also enacted to restrict protests in Manama, the nation's capital. Human rights groups say the government is working to silence its critics.
"Bahraini authorities have a record of suppressing critical news and commentary, which has had the effect of obscuring the extent of the country's unrest from the rest of the world," Mansour said from New York.
Hassan was reportedly detained for writing about the opposition.
The British government this week expressed concern about the possibility for violent demonstrations in Bahrain.
Dozens of people were killed in 2011 during a Shiite-led uprising against the Sunni-led monarchy. The government was criticized for taking a hard line against its opponents, but says it is committed to reforms outlined by a commission of inquiry probing the response to violence in 2011.