"The man in the hat" is how Belgium has come to know the country's most wanted suspect in the Brussels attacks, seen in a CCTV picture with two others who were about to blow themselves up at Brussels airport on Tuesday. The man may be a self-styled Belgian freelance journalist called Faycal Cheffou, who was charged on Saturday with "terrorist murder" and has served time for conspiracy to murder, according to Belgian state broadcaster RTBF and other media, including European media group RTL. While his identity, obscured by a floppy sun hat, glasses and a beard in last Tuesday's airport picture, has yet to be officially confirmed, prosecutors have arrested and charged "Faycal C", who Belgian media say is Cheffou. Police and government sources also say it is highly likely he was the third man seen at the airport. He was arrested right outside the federal prosecutor's office on Thursday, "stupidly hanging around", one person familiar with the investigation said, and detectives have been trying to figure out if he was reconnoitering the area for an attack on the heart of the investigation itself.

With no Facebook or Twitter account, little is known about Cheffou other than he was convicted in 2003. In an online video from 2014, he is seen reporting on an asylum centre in the Flemish town of Steenokkerzeel, northeast of Brussels, where he said Muslims were not allowed to fast during the day during Ramadan and claiming a breach of human rights.

Thought to be in his mid-thirties, Cheffou was identified by a taxi driver who drove the attackers to the airport on March 22. The two other men in the CCTV airport picture, Ibrahim El Bakraoui and Najim Laachraoui, blew themselves up, but the third man is thought to have fled. A third suitcase bomb was found at the airport undetonated.

While confident in front of camera in the 2014 video, Cheffou's former wife described him as "such a weird guy" to Belgian daily De Morgen following his arrest on Thursday night by police, while a neighbour said he was a night person. "Once it gets dark, there are comings and goings up the stairs to the top floor where he rents a studio," the neighbour told De Morgen.

After his arrest outside the federal prosecutors' office, police raided his apartment, about half a kilometre from the Maelbeek underground rail station that was also attacked on Tuesday. "In no time, they cleared the whole building," said another neighbour.

Previously, Cheffou had been detained a number of times at a park where he sought to encourage asylum seekers camped there to turn to radical extremism, according to the mayor of Brussels. Cheffou was "dangerous", the mayor told Le Soir, adding that he had since been banned from visiting the park. He was charged with conspiracy to murder at the age of 18 in 2003, while his elder brother Karim was shot dead by police in 2002, Belgian media said. A Kalashnikov and a bag filled with grenades was also found at Karim's home during a search.