Prominent Egyptian opposition figure Abdel-Moneim Aboul-Fotouh suffered two heart attacks in his prison, according to his son, as reported on Anadolu Agency.
“My father is likely to lose his life at any moment,” Ahmed Aboul-Fotouh said on Twitter.
He said his father had suffered two heart attacks “in less than 24 hours due to harsh conditions” at Cairo’s Torah prison.
A critic of Egyptian President Abdel-Fattah Al-Sisi, Aboul-Fotouh has been imprisoned since early 2018 on charges of joining an outlawed group and spreading false news.
His arrest came shortly after returning to Cairo from London, where he made an interview with Al Jazeera television during which he criticised Sisi’s regime.
Aboul-Fotouh was a former member of Egypt’s now-banned Muslim Brotherhood group before he split up to run as an independent in Egypt’s presidential election in 2012.
Muslim Brotherhood candidate Mohamed Morsi won the 2012 polls, but was ousted from power after only one year following protests against his administration.
Morsi, Egypt’s first freely elected president, died on June 17 during a trial session on “espionage” charges.