An Egyptian court has ordered the release of the sons of deposed autocrat Hosni Mubarak after time served on a corruption conviction.

The Cairo criminal court ordered Gamal, Mubarak's one-time heir apparent, and his brother Alaa, a wealthy businessman, released on Monday after they were sentenced in May to three years' prison each in a corruption case dubbed the "presidential palaces" affair by the Egyptian media.

The two were first detained in April 2011 — two months after their father stepped down during the popular uprising against him, but were later released before being convicted last summer. Their father remains held in a military hospital.