Michelle Martin was last granted release on parole after serving only half of a 30-year sentence, but cannot walk free until conditions laid out by her lawyers are met – one of which was to resettle in a convent across the border.
The 51-year-old, convicted of helping Dutroux hold victims prisoner and of starving two young girls to death, had hoped to transfer into a convent.
But Mons city prosecutor Jean-Paul Lete told AFP that "Martin's lawyers have informed us that the French convent due to shelter her has refused."
The prospect of her release triggered an outcry in both Belgium and France.
Dutroux was jailed for life in June 2004 for the kidnap and rape in the 1990s of six young and teenaged girls, four of whom died.
Just weeks ago, another Catholic retreat in France was at the centre of scandal after offering shelter to the former bishop of Bruges, Roger Vangheluwe, the pivotal figure in a church paedophilia scandal.
The disgraced bishop was sent into exile by the Vatican to undergo spiritual healing in a French monastery but within days went public on television to admit molesting two nephews. He subsequently disappeared from his Loire Valley retreat.