RIYADH : Saudi Arabia's Supreme Court has rejected an appeal against the death sentence passed this year on cleric Sheikh Nimr al-Nimr who had called for pro-democracy demonstrations and whose arrest in 2012 spurred protests in which three died.

Nimr's brother, Mohammed al-Nimr, told Reuters that the sentence had been upheld after hearings that took place without his lawyers or family members being given prior notice. His life now hangs on the possibility of a pardon from King Salman.

Nimr and six other Saudis, including his nephew, Mohammed al-Nimr's son, Ali, have been sentenced to die and then have their bodies publicly displayed in the most severe penalty available to judges in the kingdom.

"We don't want anything to happen to him or to Ali or the other young men," Mohammed al-Nimr said.

Three of those were killed in protests in the two days after Nimr's arrest, as well as one policeman. The deaths were all officially described as happening after exchanges of fire prompted by shooting or petrol bomb attacks on police, but local activists said many occurred during peaceful protests.

Nimr had long been regarded as the most vocal leader in Qatif, willing to publicly criticise the Al Saud ruling family and call directly for elections. But he was careful to avoid calling for violence, analysts say.

Saudi Arabia's Interior Ministry still accused him of being behind attacks on police alongside a group of other suspects it said were working on behalf of the kingdom's main regional rival Iran.