The were more than 100 injuries on 15-year-old Kristy Bamu’s body when he was drowned in a bath in an east London flat on Christmas Day 2010.
His sister Magalie and her boyfriend Eric Bikubi, who have been found guilty of murder, believed he was possessed by an evil spirit which had to be driven from him.
The belief in Kindoki, a kind of witchcraft, is not uncommon in DR Congo, but there are concerns about how it is following migrants into their new communities in Europe.
Angus Crawford reports.