Egypt's former president Hosni Mubarak has been declared clinically dead by his doctors, the country's state news agency says.
Mubarak was moved out of prison to a military hospital after the 84-year-old ousted leader suffered a stroke and his condition rapidly deteriorated.
Medical sources told MENA that Mubarak's heart stopped after efforts to resuscitate him failed.
Mubarak was transferred to Maadi's military hospital amid tight security measures. Media personnel were denied entry to the hospital.
Mubarak was named President Anwar Sadat's deputy in 1975 and was at his side when Sadat was assassinated in October 1981 by Islamist militants.
He ruled with an iron fist, imposing Egypt's infamous emergency law, which gave Mubarak and his security forces sweeping powers to crack down on dissent and curb basic freedoms.
Mubarak ruled Egypt for almost 30 years until he was swept from power in an 18-day wave of mass protests in February 2011.
Mubarak was sentenced to life in prison on June 2 for failing to stop the killing of protesters in last year's uprising that led to his ouster.