A Bahrain appeals court on Thursday acquitted activist Nabeel Rajab, who had been sentenced to three months in jail for alleged insults issued via Twitter, but he must still serve a three-year term for taking part in protests, a judicial source said.
The Shiite human rights activist had been handed a three-month jail sentence on July 9 for alleged insults made on Twitter to members of the Sunni community which was overturned on Thursday.
Rajab, 48, will remain in jail, however, after he received a three-year sentence on August 16 for "unauthorised" protests against Bahrain's Sunni monarchy.
The appeal process in that case is due to start on September 10, his lawyer said.
Rajab complained during Thursday's hearing of suffering "physical and psychological torture" whilst under arrest, according to defence lawyers.
He said he had been kept in solitary confinement in a "dark cell" and was refused contact with family members, they added.
The head of the Bahrain Centre for Human Rights, Rajab led anti-government protests following a brutal crackdown on Shiite-led demonstrations against the regime in March 2011.
He had insisted on demonstrating inside Manama, unlike the main Shiite opposition which now stages protests in villages, after last year's clampdown on protesters who occupied the capital's Pearl Square for a month.
Recent protests demanding the release of Rajab in Shiite villages surrounding Manama have been put down by security forces using tear gas and shotguns, according to witnesses and residents.
Security forces on Friday shot dead a 16-year-old Shiite boy in Sunni-dominated Muharaq, the town at the centre of Rajab's alleged insults.
Prime Minister Khalifa bin Salman al-Khalifa on Wednesday sought to reassure Muharaq's inhabitants on a visit there, telling them the town was crucial to "the security stability of the country," Bahrain's BNA news agency reported.
Human rights groups and Western powers have urged Bahrain to overturn the three-year sentence and release Rajab immediately from jail.
Amnesty International described the sentence as "a dark day for justice in Bahrain."
EU foreign affairs Chief Catherine Ashton said she expected "that this sentence... will be reconsidered in the appeal process."
Bahrain, which is ruled by the Al-Khalifa dynasty, has come under strong criticism from international rights organisations over last year's crackdown on demonstrations that were inspired by the Arab Spring uprisings.