A teenage boy died after he was tortured and then drowned because a relative suspected him of being a witch, prosecutors told a court in the U.K.
Prosecutors said Kristy Bamu, 15, begged to die because he was in such pain from repeated attacks on Christmas Day, 2010.
They said Bamu eventually drowned after being forced into a bathtub and doused with cold water.
It is not clear if he was still conscious at the time.
Prosecutor Brian Altman told the court Thursday that Bamu had more than 100 injuries inflicted by sticks, a metal bar, a hammer and a chisel.
Bamu's sister Magalie and her partner, Eric Bikubi, are on trial in the Old Bailey court. They deny killing the boy.
Altman told the court that other siblings were also placed in the bath to be spayed with cold water by Bikubu on the day Bamu died, the U.K.'s Press Association news service reported.
Two of Magalie Bamu's sisters, Kelly, 20, and an 11-year-old, had traveled from their home in Paris, France, to spend the holidays with her and Bikubi in London, the news service added.
Kelly said Bikubi had accused her, her sister and Kristy of "being witches or sorcerers — practicing witchcraft — and adversely influencing his three-year-old son," the Press Association reported.
Altman said this was denied, but "Magalie Bamu joined her boyfriend in repeating these fantastic claims and participating in the assaults," according to the news service.
"They beat the three of them, refusing to let them eat, drink or sleep for days while the punishments being meted out became increasingly violent, with them using many implements found in the flat as weapons of torture," he added.
"However, it was Kristy who became the focus of Bikubi's attention and, in a desperate attempt to prevent any further suffering, he and his two sisters were eventually to admit to being sorcerers. Wickedly, the defendants also recruited sibling against sibling as vehicles for their violence," he said.