Belgian police issued a new appeal on Monday for information about a man caught on CCTV at Brussels airport with two others thought to have blown themselves up in the check-in area last Tuesday.

The man, seen pushing a trolley with a suitcase on it in video footage released along with the appeal, has been dubbed "the man in the hat" and named by Belgian media as Faycal Cheffou, a self-styled freelance journalist.

A source close to the investigation, speaking on condition of anonymity, said a man arrested and charged with actual and attempted terrorist murder, who prosecutors named only as Faycal C, was believed to be Cheffou.

But the source repeated that there had been no official identification, implying police may be having difficulties linking him to the figure captured on CCTV, who was wearing glasses and whose hat was pulled down over his face.

The official police notice said they were seeking to formally identify the man, who is suspected of dumping his case, which contained a bomb, before running from the terminal, and called for information.