Al-Siyoufi was detained overnight after security forces attacked the channel’s bureau in Cairo on Saturday under the pretext that the office lacked official permission.
Security forces also confiscated news equipment.
Al-Siyoufi’s arrest was condemned by Egyptian journalists, who staged a sit-in to protest against his arrest.
At home, Iranian officials also blasted the attack against al-Alam office and the arrest of its chief.
Iran’s Foreign Ministry spokesman Seyyed Abbas Araqchi in a statement said he was shocked by the attack on al-Alam office.
Iran’s Minister of culture and Islamic Guidance Seyyed Mohammad Hosseini and former parliament speaker Gholam-Ali Haddad Adel also denounced the move and called for the swift resumption of the bureau’s activity.
MRKD/HH