Michelle Martin was expected to enter a nunnery and won't be allowed to live within a 62-mile radius of any of her and Dutroux's victims, the British newspaper The Daily Telegraph reported.
A Belgian court authorized Martin's release after accepting her application for parole last year.
Dutroux was sentenced to life in prison in June 2004 for the kidnap and rape of six young and teenage girls during the 1990s, four of whom were murdered.
Martin, 52, has been behind bars since 1996 and was convicted in 2004 of being Dutroux's accomplice in the deaths of two girls.
The couple since divorced.
The announcement of Martin's release drew protests from the parents of her and Dutroux's victims, the Telegraph said.
"We still know nothing of the release plan," said Jean-Denis Lejeune, father of Julie, 8, who was raped and murdered by Dutroux. "Legally, we are in a state of helplessness. We cannot do anything except scream. But no one hears us."
Authorities had refused Martin's parole request three times before.