Former Egyptian intelligence chief Omar Suleiman has died in the United States while undergoing medical tests.
Mr Suleiman, who was 76, was one of ousted president Hosni Mubarak's closest associates.
An aide to Mr Suleiman said preparations were under way to bring his body home for burial.
A senior Egyptian intelligence official, who did not want to be named, said he had spoken to Mr Suleiman's son-in-law who confirmed his death.
Mr Suleiman stepped briefly into the limelight last year when he was made Mr Mubarak's vice president a few days before the unpopular leader was ousted in a street revolt.
The gamble failed when Egyptians massed in the streets to demand Mubarak's removal and rejected the political concessions offered by Mr Suleiman to appease the protests.
Mr Suleiman had headed the Egyptian General Intelligence Services since 1993, taking on a prominent diplomatic role in Egypt's relations with Israel, Palestinian factions and the US.