A top Bahraini court upheld a 15-year jail term for 14 demonstrators on Monday after they were convicted of killing a Pakistani in Manama during the 2011 uprising, a judicial source said.
The Court of Cassation announced its verdict in the presence of 12 of the accused, the source said, adding that the remaining two had been tried in absentia.
A court convicted the defendants of beating the victim to death "for terrorist purposes", the source said, citing the charge sheet.
Lawyers for the defendants said their clients were "tortured" while in custody in 2011, and no action has been taken in response to their complaints.
A semi-military court established under a state of emergency in 2011 had originally sentenced the men to life in prison, but an appeals court reduced the sentence to 15 years in December last year.
Cases of beatings and torture in Bahraini jails to pressure inmates to sign confessions are regularly documented by human rights groups.
Scores of participants in the Bahraini uprising have been jailed over accusations of involvement in violence since protests against the ruling Khalifa dynasty erupted in February 2011.
Despite a heavy-handed crackdown by security forces in mid-March 2011, supported by Saudi-led Gulf troops, protesters quickly returned to the streets, where they frequently clash with police.
At least 88 people have been killed in Bahrain since February 2011, according to the Bahraini Center for Human Rights.