A Saudi Muslim preacher died in prison on Tuesday evening after spending three years in detention for sending a letter of advice to the office of the Saudi monarch, according to the "Prisoners of Conscience" Twitter account, which monitors the situation of Saudi political prisoners.
Sheikh Fahd Al-Qadi was one of the most prominent clerics of the reformist "Sahwa" movement which appeared in the 1990s and has been persecuted by Saudi authorities in recent years.
Riyadh has accused some clerics associated with the movement of being members of the banned Muslim Brotherhood.
Al-Qadi was sentenced to six years in prison last month
according to the Prisoners of Conscience Account. Al-Qadi’s family accuse authorities of denying him adequate medical treatment, which led to his death.
Before his imprisonment, Sheikh Fahd Al-Qadi was based in the Al-Qassim region of central Saudi Arabia, a stronghold of the Sahwa movement.
He became well known for his work with the Committee for the Promotion of Virtue and Prohibition of Vice - also known as the Religious Police - which enforced Islamic rules and mores on society.
Al-Qadi opposed the loosening of social restrictions and called for the preservation of a conservative society.
This has coincided with increasing political repression that have ridden roughshod over human rights.
Al-Qadi's letter of advice to the king concerned what he saw as "transgressions" in the education ministry.
He was arrested for "incitement against the authorities".
Thousands of political prisoners are believed to be held in Saudi Arabia. They include prominent clerics such as Salman Al-Awdah, a famous Islamic author who was arrested in 2017 and is now under threat of execution.
Liberal and women's rights activists, such as Loujain al-Hathloul, have also been [imprisoned\.
Hathloul's family allege that she was tortured for her role in the women rights movement.
Last August, another cleric, Sheikh Saleh Al-Dumairi, died in prison in the Al-Qassim region after not receiving treatment for his heart condition.