The leader of Egypt's Muslim Brotherhood, Mohamed Badie, has suffered a non-fatal heart attack in jail.
Badie has been detained at Torah prison on the outskirts of Cairo.
According to the Guardian, state broadsheet al-Ahram reported that Badie had suffered a cardiac arrest while in prison, but he has since recovered.
State news agency MENA denied a report that Badie had died, while Brotherhood spokesmen did not respond to immediate requests about his health.
Sherief Abuel Magd, a longtime Muslim Brotherhood member and a friend of Badie's, said he could not confirm the report.
According to the report, Magd claimed that any injury to the group's leader would not impede the Brotherhood's long-term future.