State security prosecutors are questioning Gamal and Alaa Mubarak, the sons of former president Hosni Mubarak, on Monday, in connection with the corruption investigation widely-known as the "presidential palaces" case.
The brothers, along with the former president, are charged with squandering LE1.1 billion in public funds, and illicitly re-directing state funds allocated for the renovation of presidential palaces towards private residences.
The three men are currently being detained in Tora prison, south of Cairo, pending investigation into the case.
On 16 April, Egypt's state security prosecution ordered Gamal and Alaa Mubarak to be detained for a further 15 days for investigation into the charges.
On 7 April, Hosni Mubarak received a 15 day extension to his detention pending further investigations into the same charges.
Mubarak is also facing a retrial on charges related to the deaths of protesters during the January 2011 uprising.