The two sons of the ousted Egyptian president, Hosni Mubarak, have an estimated $340 million in Swiss bank accounts, a senior Egyptian justice ministry official says, according to media reports.

Assem al-Gohary said Swiss authorities were investigating whether one of the sons, Alaa, was involved in money laundering along with other former regime figures.

In Egypt, Mubarak and his sons have been charged with corruption and all three are under arrest. Mubarak is also charged with complicity in the killing of about 850 protesters during the Egyptian uprising between 25 January and 11 February this year.

As previously reported, Switzerland has already frozen the assets of the Mubarak family and other former regime figures, which Gohary estimated at nearly $450 million. He added that most of those assets belonged to the sons.

The swift move by the Swiss banking authorities to freeze the assets suggest that the Alpine state is keen to head off criticisms that it is a haven for illicit funds due to its bank secrecy laws.