An Egyptian military court acquitted him Monday, and he was set to be released Tuesday, CNN reported.
Zawahiri was extradited from the United Arab Emirates after being accused of having ties to the 1981 assassination of former Egyptian President Anwar Sadat. While he was acquitted of assassination charges, he was later accused of conspiring against the government. He was released briefly with several other political prisoners last year, but arrested again shortly after.
Mohamed's son, Ahmed, said officials persecuted his father because he was the bother of the al-Qaida leader. "He paid a high price for being Ayman's brother and he has denounced any sort of violent ideologies now that his main enemy, the Mubarak regime, has been removed," he said.
Mohamed is a member of the Egyptian Islamic Jihad, classified by the United States as a terrorist group, which merged with al-Qaida in 2001.