The boyfriend is now in detention in Hasselt, but prosecutors are not willing to provide any further details.
In December of last year 32-year-old Elke Wevers left her flat in Neeroeteren (Limburg) bound for her work. A colleague was supposed to give her a lift, but she sent a text saying that she didn't feel well and was returning home.
The woman's boyfriend and family suggested that she had been abducted. Last week, a year after her disappearance, a torch-lit parade was staged to mark the anniversary.