Qassem Hossein, an Iranian diplomat working at the Iran mission in Cairo, was arrested and interrogated, but security sources didn't say if he remained in custody or provide details about his diplomatic status, Bikya Masr reported Sunday.
Bikya Masr said reports from other news agencies claimed Hosseini was being held for "passing information" from the Cairo mission to Tehran.
Even though diplomatic ties between the two countries was severed as a result of Iran's Islamic revolution in 1979, both countries have maintained embassies in the others' capital.
Last month, Kuwait and Bahrain expelled several Iranian diplomats following a court verdict in Kuwait linking the diplomats with a spy ring operating in Kuwait.
Jordana Brewster on Paul Walker: 'He was an enormous presence in my life'
Exploding whale video goes viral on Internet