The suspect, named in the press as 42-year-old Ahmed Ali, is accused of participation in 13 terror attacks, and with being a commander of the militant Helwan Brigades group.
The Helwan Brigades, a militant Islamic group named after a district in the south of Cairo, has been accused by Egyptian authorities of carrying out terrorist attacks, and of being affiliated with the Muslim Brotherhood.
The Egyptian media has linked the arrest of Ahmed Ali with a series of arrests in recent weeks of individuals by the Egyptian authorities on charges of belonging to militant organizations, some of whom have since been reported missing.
According to reports, another US Embassy employee, 44-year-old Ahmed Amin Suleyman, was arrested by the authorities on May 26, and was reported missing on June 1.