Belgian Federal Police
The federal prosecutor's office could not immediately be reached for comment.
In a statement on Friday, it had named as "Faycal C" one of three men police had detained near the federal prosecutor's office, the heavily guarded center of the investigation effort.
Various media outlets, including Belgian newspaper De Morgen, are reporting that Cheffou was a freelance journalist who lived in an apartment close to Maelbeek metro station.
Police reportedly uncovered a Kalashnikov rifle and a bag filled with grenades during a raid on Cheffou's home following his arrest, Belgian daily regional newspaper La Capitale reported.
Cheffou was reportedly known to police for a criminal record that involved drugs and violence, but had not been previously linked to terrorism, according to La Capitale. Police reportedy suspected Cheffou of recruiting refugees to be jihadists in late 2015.
Le Soir newspaper said Faycal C was identified by a taxi driver who drove the attackers to the airport. Earlier it had quoted police sources as saying it was highly likely Faycal Cheffou was the third man.
Other media also carried similar reports and said Cheffou was a freelance journalist.
Nine people in total have been arrested since Thursday in Belgium and two in Germany, as European authorities swoop on Islamic State militants they link to the Brussels bombings that killed 31 people and to the attacks in Paris last November that killed 130.