Rights groups say its poor conditions fall far below Egyptian and global standards.
While Middle East Eye can not independently verify the account, details have been corroborated by other reports of the court session seen by MEE and sources familiar with Morsi's case. "However this isn't really up to the family but for the powers that be", he said.
A medical source said Mursi died of a heart attack. He was taken to a Cairo hospital but could not be revived.
Last year, a group of visiting British parliamentarians said his "inadequate care" would likely cause a "rapid deterioration of his long-term conditions, which is likely to lead to premature death".
The Muslim Brotherhood, Egypt's most powerful Islamist group, won the elections held after Mubarak's fall, considered the first free votes the country had seen. After a narrow victory, he promised to head a government "for all Egyptians". The stocky, bespectacled man, born in 1951 in the dying days of the monarchy, told Egyptians he would deliver an "Egyptian renaissance with an Islamic foundation".
FILE- Egyptians wave national flags and hold pictures of Egypt's Defense Minister Gen. Abdel-Fattah el-Sissi, during a rally in Tahrir Square, in Cairo, Egypt, Saturday, Jan. 25, 2014.
The Brotherhood's political wing - the Freedom and Justice Party - accused Egyptian authorities of "deliberately killing him slowly".
A few minutes afterwards, he collapsed in the cage, the official said, speaking on condition of anonymity because he was not authorised to talk to the press.
No recent injuries were found on the body of the outlawed Muslim Brotherhood leader Mohamed Morsi, said Egypt's Attorney General Nabil Sadek in a statement on Monday. A heavy security presence was outside the prison on Monday night. He had denied the charges.
"The West has remained silent", Erdogan said.
He added, "I offer my condolences to all of my brothers who walked the path with him".
During the 2011 revolution, Egypt's Morsi and members of the Muslim Brotherhood escaped from Wadi al-Natroun prison.