A leading Bahraini human rights activist was denied bail on Tuesday on charges of writing an editorial critical of the government, a pro-opposition rights group reported.
The Bahrain Institute for Rights and Democracy added that Nabeel Rajab's health is deteriorating after he underwent an operation last month for bleeding ulcers.
There was no immediate government comment on the report.
Rajab was a leading figure in a 2011 pro-democracy uprising led by Bahrain's Shi'ite Muslim majority and he has been repeatedly detained.
In a New York Times column published under his byline in September, Rajab addressed readers in the first person, saying he was writing from a "Bahraini jail cell where I have been detained, largely in isolation, since the beginning of summer".
The column said Bahrain was a country "that has subjected its people to imprisonment, torture and even death for daring to desire democracy".
Rajab faces a separate trial for tweets he is accused of making about the Gulf Arab kingdom's prison system and its involvement in the war in Yemen.
The United Nations Committee against Torture on Friday called on Bahrain to release Rajab from more than nine months of solitary confinement and investigate widespread allegations of ill-treatment and torture of detainees.
Bahrain denies any systematic abuse by police or in its prisons and says it is facing a violent uprising backed by its regional rival Iran.