The Muslim Brotherhood held Egypt's interim authorities responsible for the safety of the group's detained leaders and members, topped by Muslim Brotherhood Supreme Guide Mohamed Badie.
Local media reported earlier this week that Badie had suffered a heart attack in Tora Prison south of Cairo.
Badie's family dismissed the reports, however, saying his wife and daughter had visited him on Sunday and confirmed that the 70-year-old Islamist leader was in good health.
"The only thing he complained about was being held in solitary confinement without being allowed to leave his cell or meet any other detained Brotherhood members," son-in-law Ahmed Hussein was quoted as expressing on the Brotherhood-affiliated Freedom and Justice Party website.
Badie told his visitors that, during his arrest, he had received a punch in the face that knocked off his glasses and dentures, Hussein said, adding that Badie had got both items back days later.
In a statement, the Brotherhood said that authorities were dealing with detained "anti-coup" protesters more harshly than the treatment doled out to detained former officials of the Hosni Mubarak regime.
Badie, along with deputies Rashad al-Bayoumi and Khairat al-Shater, faces charges of "inciting violence and murder" in connection with clashes outside the group's Cairo headquarters earlier this year in which ten people were killed.
He is currently being held in the high-security Tora prison, where many other detained group leaders have been kept since the military's July 3 overthrow of President Mohamed Morsi, who himself hails from the Brotherhood.
Egyptian authorities have unleashed a massive crackdown on the Islamist group since the violent August 14 dispersal of two pro-Morsi sit-ins, in which hundreds of demonstrators were killed.
englishnews@aa.com.tr
