In a joint statement issued Wednesday, 51 human rights organizations called for the immediate release of Salah Soltan, an Egyptian-American legal scholar and the father of a prominent US human rights defender.

Soltan, a former professor of Islamic Law at Cairo University and founder of the Islamic American University in Michigan, was arrested in Egypt in 2013 on charges related to his opposition of the military’s ousting of elected president Mohamed Morsi. In 2017, a court sentenced him to life in prison in a mass trial marred by due process and fair trial violations. The organizations — which include Human Rights Watch, Amnesty International and other major international advocacy groups, as well as myriad locally-focused groups — believe Soltan’s arrest was in fact carried out to retaliate for the human rights advocacy work of his son, Mohamed Soltan.

Imprisoned in Egypt’s notorious Badr 1 prison, Soltan suffers from life-threatening health conditions, the organizations say, including heart and liver diseases, and has reportedly endured tortured and other forms of ill treatment. The Egyptian authorities have failed to provide Soltan with adequate health care, despite independent doctors warning that he is at “increased risk of sudden death” due to his health, per the statement.

Human Rights Watch’s Deputy Middle East and North Africa Director, Adam Coogle, said:

On top of railroading him in an unfair trial, Egyptian authorities are deliberately abusing Salah Soltan’s rights by failing to provide him with health care. … The authorities should at minimum transfer him to a qualified medical facility where independent health professionals can treat him without hindrance.

In addition to criticizing the Egyptian government for its treatment of Soltan, the organizations called on US authorities to do more to advocate for the rights of those of its citizens who are unlawfully detained abroad.