The wealth of the Egypt's first family was built largely from military contracts during his days as an air force officer; Mubarak eventually diversified his investments through his family when he became President in 1981, the 'ABC News' quoted experts as saying.
Amaney Jamal, a political science professor at Princeton, said those estimates are comparable with the vast wealth of leaders in other Gulf countries.
"The business ventures from his military and government service accumulated to his personal wealth. There was a lot of corruption in this regime and stifling of public resources for personal gain," Jamal was quoted as saying.
Jamal said that Mubarak's assets are most likely in banks outside of Egypt, possibly in the UK and Switzerland.
"This is the pattern of other Middle Eastern dictators so their wealth will not be taken during a transition. These leaders plan on this," she said.
Mubarak, his wife and two sons were also able to accumulate wealth through a number of business partnerships with foreigners, according to Christopher Davidson, professor of Middle East Politics at Durham University in the UK.
The Mubarak family owns properties in London, Paris, Madrid, Dubai, Washington, New York and Frankfurt, according to a report from IHS Global Insight.
Aladdin Elaasar, author of 'The Last Pharaoh: Mubarak and the Uncertain Future of Egypt in the Obama Age', said the Mubaraks own several residences in Egypt, some inherited from previous presidents and the monarchy, and others he has built.
"He had a very lavish lifestyle with many homes around the country," said Elaasar, who estimates the family's wealth is between $50 and $70 billion.