According to Jahina newspaper, the death sentence has been referred to the interior ministry and then the king’s office for the final go-ahead.
Nimr’s lawyer, Sadeq al-Jubran, has also said that Nimr could be executed as soon as the Saudi monarch approves his sentence.
Some media outlets have even reported that Crown Prince Muhammad bin Nayef has already signed the verdict.
The UK-based rights group Amnesty International has called Nimr’s trial “deeply flawed” and the death sentence “appalling,” saying the verdict has to be quashed.
Ayatollah Nimr has been in detention since July 2012.
He was arrested following demonstrations that erupted in Qatif region. He is accused of delivering anti-regime speeches and defending political prisoners.
His arrest has sparked widespread protests in the Arab country, leaving several people dead.
Last October, Sheikh Nimr’s family reported that a Saudi judge has found him guilty of “sedition” and sentenced him to death.
At the same time Saudi authorities have detained the brother of Shia cleric Ayatollah Sheikh Nimr Baqir al-Nimr, local media said.
They said Mohammad al-Nimr was taken into custody by security forces in al-Awamiya in Eastern Saudi Arabia.
Human rights activists have voiced concerns over the latest arrest.
It came a few days after reports emerged that that the Saudi Supreme Court and an appellate court had approved the execution of Ayatollah Nimr.
Ayatollah Nimr was attacked and arrested in the Qatif region, east of Saudi Arabia, in July 2012, and has been charged with undermining the kingdom’s security, making anti-government speeches, and defending political prisoners. He has denied the accusations.
In October 2014, a Saudi court sentenced Sheikh Nimr to death, provoking huge condemnations and criticism in the Middle East and the world.
Ali Mohammed Baqir al-Nimr, the nephew of the prominent Shia cleric and the son of Mohammad al-Nimr, has been also sentenced to death over his alleged role in anti-regime protests in 2012, when he was 17 years old.
“When he joined the protest three years ago he was only 17, he was underage and he only participated in a peaceful protest, you cannot take a boy and… condemn him to death because he protested against you and he called for some political reforms, this is outrageous, this is outside any human decency,” said political activist Saeed Shehabi during the protest rally.
Muslims Community of the UK and the Shia Activists once again gathered outside the Saudi embassy in London calling on Riyadh to halt the execution of prominent Shia cleric Sheikh Nimr Baqi al-Nimr and his nephew.
The participants in the Wednesday rally held placards reading “free Sheikh Nimr” and “sentenced to death due to the idea of election system.”
“We call on Saudi Arabia to halt these executions and either release these innocent prisoners or we call for… a fair and public trial under the watchful eyes of the world,” Russia’s Ruptly news agency quoted an activist as saying.
“And we will not be silenced as you do to your citizens in Saudi Arabia,” another activist said.
Meanwhile, UN Secretary General Ban Ki-Moon has called on Saudi Arabia to halt Nimr’s execution, Press TV reported.
Speaking at the UN headquarters in New York, Ban’s spokesmen, Stephane Dujarric, said that during a phone call the UN chief had asked King Salman to overturn the death sentence against the Shia cleric.