Earlier in the day, the Egyptian Prosecutor General's office said in a statement that it had ordered its employees to establish the cause of death of former President Mohammed Morsi, who died during a trial.

The cause of death of former Egyptian President Mohamed Morsi was a heart attack, according to state TV, citing a medical source.

According to Reuters, citing Egyptian television, the former president and one of the top members of the Egyptian Muslim Brotherhood, was suffering from a benign tumor, and had been receiving continuous medical attention. 

Morsi, 67, suddenly lost consciousness and fell in the defendants' cage in the courtroom during a break between trial sessions involving an espionage case, according to the Egyptian Prosecutor General office's statement. 

A few minutes prior to his death, the former president made a five-minute speech before the judge. The unconscious politician was taken to a hospital, where he was pronounced dead. An external examination showed no damage to his body.

Following Morsi's death, Amnesty International reportedly contacted Cairo authorities and requested that they conduct "an impartial, thorough and transparent investigation."

Mohammed Morsi was removed from power in 2013 amid a wave of popular discontent caused by the leadership of the Muslim Brotherhood movement.

Following Morsi's removal from power five criminal cases were opened against him, including those in connection with clashes near the presidential palace between his supporters and opposition in December 2012; espionage in favor of Qatar and the Hamas movement; his escape from prison during the 2011 mass riots, and insulting the judiciary.