An Egyptian official says authorities have ordered the release of a presidential adviser to ousted Islamist President Mohammed Morsi after a year and half in detention, citing health concerns.

Khaled al-Qazzaz, 35, was released on Sunday, the official said Monday, speaking on condition of anonymity because he was not authorized to speak to the press.

Al-Qazzaz, a leading member of the Muslim Brotherhood group from which Morsi hails, was detained after the military ouster of Morsi in July 2013. Later he was accused of membership in a terrorist organization, a reference to the now-banned Brotherhood.

Al-Qazzaz's family said in a statement that he was held in "solitary confinement in a cramped, insect-infested cell slighter larger than a broom closet in one of Egypt's most notorious prisons."