Saudi prison
A Saudi activist could be executed any day now for his alleged role in organizing anti-government protests. Pictured, Ha'er Prison in Saudi Arabia July 6, 2015. Reuters/Faisal Al Nasser

A Saudi man accused of participating in demonstrations against the government and inciting others to do the same could be beheaded and crucified any day by the country's authorities. Ali Mohammad Baqir al-Nimr, 21, was sentenced for crimes he allegedly committed when he was 17 years old, and his case has been lambasted as "deeply flawed" and unjust by human rights activists and organizations.

In addition to the anti-government protest charges, officials claim Nimr taught others how to provide first aid. The most significant of his charges include possession of a machine gun and armed robbery. Nimr was forced to offer a false confession while in custody, human rights organizations have said. His testimony reportedly was the only evidence brought against him.

“His trial was deeply flawed,” Amnesty International has said. “He was denied the most basic needs to prepare his defense, including regular access to his lawyer and a pen and paper to respond to the charges. His defense was not allowed to cross-examine key eyewitnesses and his lawyer was not informed of the dates of a number of court hearings.”

All appeals against his execution have been exhausted, and authorities are able to execute him without offering any prior notice to his family, Reprieve, a U.K.-based human rights organization, has said. He could be executed as soon as King Salman has ratified the sentence, Amnesty International has warned. His father has appealed to the king to spare his son's life.

Nimr, who is being held in a prison in Dammam, in eastern Saudi Arabia, was sentenced following pro-democracy protests that swept through much of the Arab world in 2012 and 2013.

He is the nephew of a popular Shiite reformist cleric, Nimr Baqir al-Nimr, who also was sentenced recently to death for his criticisms of corruption and discrimination against minority groups in the Saudi kingdom. Saudi Arabia repeatedly has been accused of carrying out egregious rights abuses. Human rights organizations have charged the Saudi government with denying its citizens basic freedoms and routinely imprisoning political dissidents and human rights activists. Saudi Arabia executed 90 people this year as of May.