The decision clears the way for a criminal investigation and a possible trial of Egypt's ousted leader.
Mubarak stepped down Feb. 11 at the end of 18 days of massive protests demanding his ouster after nearly 30 years in power. He, his wife, two sons and their wives have also been banned from travel abroad.
Judicial officials described the decision in closed court to The Associated Press on condition of anonymity because they were not authorized to speak to the media.
There are no official figures on the funds held by Mubarak and his family but many believe they run into the billions, with much of it held overseas.
Egypt's attorney general froze the assets of the Mubaraks on Feb. 20 and ordered the family's funds seized eight days later. Authorities also prevented Mubarak's wife and son from flying out of the Red Sea resort of Sharm el-Sheikh, where they are thought to be staying.
During the pro-democracy uprising, unconfirmed reports that Mubarak and his family might have amassed billions, or even tens of billions of dollars, over their three decades in power, fueled protesters already enraged over massive corruption and poverty in Egypt.
Mubarak, top leaders of his one-time ruling party and other cronies, as well as the powerful military have all profited richly from the corrupt system while nearly half of Egypt's 80 million people live under or near the poverty line set by the World bank at $2 a day.
Mubarak, 82, is suspected of turning a blind eye to corruption by family members and their associates, while many of the allegations of wrongdoing centered on the business activity of his two sons, Alaa and Gamal, as well as Gamal's wife and her family.
Unlike other Arab leaders, particularly those in the oil-rich Gulf nations, Mubarak was far from ostentatious. Whatever wealth he and his family may have had was rarely - if ever - flaunted. But that did not stop Egyptians from swapping stories about the size of their wealth and the alledgedly corrupt methods they used to amass it.
The most prominent symbol of their presumed fortune that has surfaced was a townhouse in London's exclusive Knightsbridge district, which is listed under Gamal Mubarak's name and where he was said to have lived while working as an investment banker in the early 1990s. The townhouse has become a focal point for many in Egypt as foreign governments begin to either enact, or consider freezing the family's assets.
Gamal Mubarak was the ousted leader's one-time heir apparent, although they never confirmed the plan and remained evasive on the topic almost until the very end. The younger Mubarak rose rapidly through the ranks of his father's National Democratic Party, or NDP, over the past decade to become the country's most powerful politician after the president.
Several of those businessmen are now in prison and subject to criminal investigations as the ruling military pushes ahead with a campaign to cleanse the country from the corruption of the ousted regime.
Alaa Mubarak's wealth had been the subject of much speculation well before the political rise of his younger brother. There are allegations that he used the family name to muscle in on profitable enterprises, taking a cut of profits without contributing to the funds invested or work done.
Switzerland was the first foreign country to say it was moving to identify and freeze assets of Mubarak and his family.The European Union said last week it was considering a request from Egypt to freeze the assets of Mubarak's top aides. The EU said, however, that no such request had been submitted about the Mubaraks.