A lawyer in Bahrain says death sentences have been overturned for two protesters convicted of murdering two policemen during a wave of anti-government demonstrations.

Hassan Radhi, a lawyer for one of the defendants, says the Cassation Court struck down the sentences, which had been handed down by a special security court set up under a period of emergency law last year.

International rights groups have criticized Bahrain for trying protesters, opposition leaders and activists in the military-linked tribunal.

Independent investigators tasked by Bahrain's king with probing the unrest recommended authorities review convictions and sentences handed down by the special court.

Monday's decision sends the case of the two protesters to the supreme court for an appeal.