The virologist and his family have been moved to a safe house until the man, who is on Belgium's terror watchlist over his support for far-right groups, has been found.
A frantic search for an armed man in Belgium who is on the terror watchlist due to extreme right-wing politics entered its fifth day on Friday.
More than 400 specialised officers in Belgium intensified their search on Thursday for the ex-soldier, named as 46-year-old Jurgen Conings.
Conings was placed on the watchlist in February and has threatened several people in the past months, including Marc Van Ranst, Belgium's top virologist in the fight against COVID-19. Despite this he was still able to hoard heavy weapons in an army barracks before disappearing this week.
Belgian legislators expressed anguish on Thursday at the fact that the fugitive, who is believed to be armed, had still evaded capture.
“It is unacceptable that someone seen by our security services as a potential danger can still get access to arms,” Belgian Prime Minister Alexander De Croo told parliament in response to a barrage of criticism from MPs. “Procedures and internal controls must absolutely be reinforced."
Conings had a three-decade career behind him as an expert marksman before he started making threats and racist remarks on Facebook. He was subjected to disciplinary action but still permitted to work with firearms.
Army officers have been combing through the vast Lanklaarse Steenweg natural park in Niel-bij-As, northeastern Belgium. A major highway running through the park has now been closed off for two days, causing massive traffic jams.
Conings's car was found in the area in on Tuesday containing found four missile launchers and ammunition. Belgian justice minister Vincent Van Quickenborne has described him as an "acute threat".
Federal prosecutors have meanwhile accused Conings of stealing heavy weapons from the military base where he worked as an instructor, seemingly to target Belgian state officials and public figures.
After being threatened by Conings, Van Ranst was moved to a safe location until the man could be apprehended. He wrote on Twitter: "Being against COVID measures and COVID vaccines all too often coincides with aggression of violence and raw racism.
"Let one thing be clear: such threats do not make the slightest impression on me."
The Belgian authorities have meanwhile put out a bulletin warning people not to approach Conings if they see him, and asking him to turn himself in.