"Morsi died today while attending a session in his trial on espionage charges. During the session, he was granted permission to address the judge," a presenter with Egypt's state TV said.

Morsi had a history of health issues, including diabetes and liver and kidney disease. He had suffered from medical neglect during his imprisonment, compounded by the poor conditions in jail.

There have been various reports over the years that Morsi had been mistreated and tortured in jail, with activists saying on Monday his death should be seen in the context of the Egyptian authorities' systematic isolation and mistreatment of political detainees.

ILKHA