She was granted conditional release on Thursday night, according to Le Soir, which quoted her lawyer Jean Flamme.
Johnson must wear an electronic bracelet and is consigned to her home, although she may be authorized to leave for medical appointments.
She was arrested on September 17 near Ghent and charged the same day with crimes against humanity.
This was the first ever arrest for crimes committed during the first civil war in Liberia (1989 -1996).
Martina Johnson was reportedly a key figure in Charles Taylor’s National Patriotic Front of Liberia (NPFL). The NPFL launched the first Liberian civil war in 1989, giving rise to violence and human rights abuses that were to last several years.
She is suspected of participating in mutilation and mass killing in late 1992 during “Operation Octopus”, an infamous NPFL military offensive on Monrovia that left scores of civilians dead.
NPFL leader and former Liberian president Charles Taylor was sentenced in 2012 to 50 years in jail for war crimes and crimes against humanity committed in neighbouring Sierra Leone. He was tried by the Special Court for Sierra Leone and is now serving his sentence in the UK.