"My imprisoned dad's life is in danger", the son of the Egyptian prominent opponent, Mohamed Aboul Fotouh, said yesterday.
"On my last visit to my father, he told me that he was suffering angina pectoris just before I arrived," the son added, explaining that the prison administration was refusing to send Aboul Fotouh for medical examinations and treatment.
"My father is dying slowly," he stressed.
Last week, Aboul Fotouh's family said he was "medically neglected."
The announcement comes days after the death of the former first freely-elected President-elect Mohamed Morsi, who had similar conditions during his imprisonment.
The Egyptian authorities have not been immediately available for a comment, but they say that they provide "health care services to all prisoners "without discrimination."
On Tuesday, the Cairo Criminal Court renewed Aboul Fotouh's detention for an additional 45 days in connection to a case in which he is accused of "publishing false news."
Aboul Fotouh has been held in prison since mid-February 2018 "leading and reviving a banned group and publishing false news." He was arrested right after his return from UK's London where he had an interview with Al-Jazeera television, in which he criticised the incumbent Egyptian President Abdel Fattah Al-Sisi before his re-appointment for a second term in March 2018.
The prominent opponent was arrested more than once under the rule of Egypt's former President Hosni Mubarak. He had run for the presidency in 2012.