It said Morsi had fainted after a court session and died afterward. He was pronounced dead at 4:50 pm local time according to the country’s public prosecutor.
"He was speaking before the judge for 20 minutes then became very animated and fainted. He was quickly rushed to the hospital where he later died," a judicial source said.
"In front of Allah, my father and we shall unite," wrote Ahmed, Morsi’s son on Facebook.
Turkish President Tayyip Erdogan paid tribute to Morsi saying, "May Allah rest our Morsi brother, our martyr's soul in peace.”
According to medical reports, there were no apparent injuries on his body.
Morsi, who was democratically elected after the popular ouster of Hosni Mubarak, was toppled by the military led by coup leader and current President Abdul-Fattah el-Sissi in 2013 after protests against his rule.
"We received with great sorrow the news of the sudden death of former president Dr. Mohamed Morsi. I offer my deepest condolences to his family and Egyptian people. We belong to God and to him we shall return," Qatari Emir Sheikh Tamim bin Hamad Al Thani wrote on Twitter.
Morsi was allowed 3 short visits in 6 years. One in November 2013 after being forcibly disappeared for 4 months, and another in June 2017 when only his wife and daughter were allowed, and the third in September 2018 with security official recording the whole conversation.
He was facing at least six trials for politically motivated charges according to his supporters. The former president was also serving a 20-years prison sentence for allegedly killing protesters in 2012.
Morsi was suffering from various health issues including diabetes and liver and kidney disease. During his imprisonment, he suffered from medical neglect worsened by poor prison conditions.
Mohammed Sudan, a leader of the Muslim Brotherhood, said that Morsi’s death was "premeditated murder” by not allowing him adequate health care.
"He has been placed behind [a] glass cage [during trials]. No one can hear him or know what is happening to him. He hasn't received any visits for months or nearly a year. He complained before that he doesn't get his medicine. This is premeditated murder. This is a slow death,” Sudan said.