Two Bahraini policemen were sentenced to jail for seven years each on Sunday for beating to death a Shi'ite opposition activist in custody during last year's crackdown on protesters.
The sentences, reported by state news agency BNA, were criticised as too lenient by critics and may do little to blunt international criticism of human rights abuses since Bahrain's Sunni Muslim rulers quelled a Shi'ite-led uprising last year.
In April 2011, Kareem Fakhrawi - a businessman and member of Wefaq, the leading opposition group in Bahrain - died in custody, a week after failing to return home from a police station where he had tried to complain about his house being demolished by police, opposition members said.
"We didn't expect it would be just seven years," said Wefaq member Sayed Hadi al-Mousawi, criticising the sentences.
"The prosecutor changed the charges from 'torture leading to death' to 'beating leading to death'. They don't want to admit that there was torture," he told Reuters.
In July, Bahrain charged 15 policemen with "mistreatment" of detainees, as part of an investigation into reports of torture of protesters rounded up in a crackdown on unrest.
In pursuing prosecutions over torture, Bahrain has in part been responding to US calls for justice and reform - a sensitive issue because the Gulf state hosts the US Navy's Fifth Fleet and wants to be able to keep buying US arms.
A commission of international legal experts reported in November that torture had been systematically used to punish and extract confessions from hundreds of protesters during the period of martial law last year.
It also said that 35 people, mainly protesters, had died during the unrest, five of them as a result of torture.
Thousands were arrested and military trials were instituted during the martial law period.
Washington has called on its ally to talk to the opposition, but unrest has continued. Police and demonstrators clash almost daily and each side blames the other for the violence.
The opposition says little progress has been made towards its demands for reforms including a parliament with full powers to legislate and form governments. Many Shi'ites complain of political and economic marginalisation, a charge the government denies.
Bahrain's interior minister has denied that police were given any orders to torture or kill protesters.