A spokesman for Westminster Coroner's Court said an inquest would open on Friday into a man named Ashraf Marwan, but did not give any further details.
Egypt's MENA news agency quoted a source close to the family as saying Marwan had recently suffered from balance problems because of an illness and had been using a cane.
Marwan had been living in London after leaving Egyptian government service late in the 1970s.
He is thought to have feared for his life after he was publicly accused of being a spy for Mossad three years ago.
Israeli media named his as a source for the Israeli secret service, saying he had passed a warning to Mossad, the Israeli intelligence agency, on the eve of the 1973 Middle East war, also called the Yom Kippur War.
Yom Kippur 'tip-off'
Gad Shimron, a former Mossad officer turned historian, said Marwan had warned Israel hours before the Egyptian attack in 1973.
"We know now, from testimony given by Israeli spymasters and made public years after the Yom Kippur War, that Marwan was the man who tipped off the Mossad," he said.
According to The Times, a UK newspaper, Marwan offered his services to Israel in 1969, going on to provide information on Egypt and the Arab world.
He worked as a senior information official for both Abdel Nasser and Anwar Sadat, Abdel Nasser's successor as president.
Egyptian media has said he also had "intelligence duties".