Assem al-Gohary says Swiss authorities are investigating whether one of the sons, Alaa, was involved in money laundering along with other ex-regime figures.
At home, Mubarak and his sons have been charged with corruption. Switzerland has already frozen the assets of Mubarak and his associates. Al-Gohary says most of those assets belong to the sons.
Egypt's attorney general froze assets of the former presidential family on February 20, in the aftermath of 18-day uprising that ousted Mubarak.