Belgium's highest court has granted conditional early release to the ex-wife of convicted Belgian murderer and paedophile Marc Dutroux.

The Court of Cassation ruled that no procedural errors were made by a lower court to allow Michelle Martin to live in a convent after serving less than half of her 30-year sentence.

Martin was convicted after allowing two eight-year-old girls to starve to death in the couple's basement, after her husband had kidnapped and imprisoned them.

The Dutroux case still haunts Belgium. The saga of abduction, imprisonment, rape and murder of young girls revealed the depths of human depravity, and exposed a judicial system that failed the most vulnerable.

In total Dutroux abducted, imprisoned and raped six girls in the mid-1990s, two of whom he murdered.

Two of the girls were later found buried alive, while on one occasion police, who were searching his house, heard voices in the basement, but failed to take action.

Martin knew the two girls were trapped in the couple's basement while her husband served a prison term for car theft, yet she neither released them nor fed them. They eventually starved to death.

Under Belgian law she was eligible for parole after one-third of her sentence was served, but the decision has triggered outrage.

The Clarisse nuns in the village of Malonne say she deserves forgiveness and her lawyer said she had become deeply religious and was unlikely to reoffend.

Dutroux is still serving a life sentence and is unlikely to be released.