The suspected "leader of the terrorist network" disbanded in Morocco, Belgian-Moroccan Abdelkader Belliraj, had been questioned in Belgium in 1989 for the murder of the rector of the Great Mosque, Abdullah al Ahdal, reports Le Soir. The man was interrogated and then set free since there was not enough evidence to keep him under arrest.
The paper emphasizes that according to the information, dozens of Belgian-Moroccans had been arrested in Morocco and not just three. They are mainly known for banditism.
Source: HLN (Dutch)
See also: Belgium: Terrorist leader committed six murders, Belgium: Wife of murder-terrorist suspect denies connection to murders