A young teenager watched his brother drown in a bath after being tortured over claims he was a witch, a court heard today.
The 14-year-old, who cannot be named for legal reasons, said he saw his sibling Kristy Bamu attacked with weapons including a hammer and weight bar before he died.
Part of a video of the account that the brother gave to police was played to a jury at the Old Bailey today.
Kristy and four of his siblings had gone to stay with their sister Magalie Bamu at her flat in Forest Gate, east London, in December 2010.
While they were there, the court heard she and her partner Eric Bikubi accused them of being witches and trying to control another child.
Bikubi found a pair or urine-soaked underpants in the kitchen of the flat, and eventually Kristy admitted that he had wet himself.
This triggered a brutal outpouring of violence by Bikubi, who believed this was due to witchcraft, the court heard.
The 14-year-old said: "He said how can a boy of your age wee himself in the bed. [Kristy] said it started happening as he was getting up to go to the loo, but he didn't want to believe him. [Bikubi] said it was witchcraft."
The following day Bikubi questioned them all until the early hours of the morning.
He insisted that they would have little food or sleep until their autistic brother Yves, now 23, started to behave in the same way as them, jurors heard.
"He said we are going to do this for three days," the brother told the court. "We are going to remain like this ... we are going to eat very little and to sleep very little until Yves's behaviour has become like ours and is normal."
Bikubi later attacked Kristy with a dumbbell bar and a stick, threatening to kill him, the court heard.
He forced the siblings to hold him in a prone position as he smashed four floor tiles over his head, and later hit him with a hammer, the jury was told.
Through terror Kristy admitted to being a sorcerer, and to having a mission to kill Bikubi and Magalie Bamu, as well as another child of the family.
The brother said: "Then he [Bikubi] called my father. He said you have to come because I'm going to kill him. He said it wasn't a joke.
"I don't know if he [the father] thought it was a joke. He said he was going to come on Monday."
Bikubi forced Kristy to get into the bath and hosed him down with cold water. He was too badly injured to get up, the court heard.
Speaking through a French interpreter, the brother said: "My brother was still not moving and Eric noticed that he wasn't moving.
"He took hold of him, putting him on the ground. He wanted to give him heart massage but it didn't work. My sister Magalie wanted to call the ambulance service but he said 'no wait'. He kept trying but it didn't work."
Magalie Bamu and Bikubi, both 28, of Hathaway Crescent, Newham, east London, deny murdering Kristy.
Bikubi has admitted manslaughter on the grounds of diminished responsibility, and two counts of causing actual bodily harm to two of Kristy's sisters. Bamu denies the two counts of ABH.
The trial was adjourned until Monday.