A couple has been found guilty of the murder of a teen boy they accused of using witchcraft.

Sky News reports that football coach Eric Bikubi and partner Magalie Bamu, brutally tortured her younger brother Kristy for four days.

Both Bikubi, 28, and Bamu, 29, from east London, denied killing Kristy, according to the BBC.

Kristy reportedly travelled to London from Paris to spend the Christmas holidays with his eldest sister in 2010. The Old Bailey was told that while there the couple, under the belief that Kristy has cast spells on another family member, drowned in a bath during a torture to produce exorcism.

Sky News reported that tests found that Kristy suffered 101 injuries. Claims are that he was attacked with knives, sticks, metal bars, a hammer and chisel and that he begged to die: before he slipped under the water.

Kristy was reportedly tortured because he refused to admit to sorcery and witchcraft.

Both killers are from the Democratic Republic of Congo and Sky News reports that Bikubi sought the advice of pastors in London. Kristy's torture went beyond the deliverance services carried out in African churches, according to Sky News.

The Old Bailey jury also heard that Bikubi and Magalie Bamu didn't allow the other children to sleep for four days, made them fast and forced them to pray.

Sky News reported that Judge David Paget told the jury of seven women and five men that he was exempting them from jury service for the rest of their lives because the case was so harrowing.

It is a case we will all remember, he told them, adding that court staff will offer help.

Kristy's father, Pierre, issued a statement that read: Kristy died in unimaginable circumstances at the hands of people he loved and trusted, people we all loved and trusted. I feel betrayed. How could they accuse, judge and sentence?

To know that Kristy's own sister, Magalie, did nothing to save him makes the pain that much worse.