The parents of a boy tortured to death for being a "witch" did not realise what was happening despite a "huge number" of phone calls, a court heard.
Kristy Bamu, 15, from Paris, was found dead in a bath in a flat in Newham, east London, on Christmas Day in 2010.
His sister Magalie Bamu and her boyfriend, Eric Bikubi, both 28 and living in Newham, deny the murder.
His other sister Kelly Bamu, 21, said that along with Kristy, she was forced to tell her parents they were witches.
Giving evidence through an interpreter, Miss Bamu told the Old Bailey Mr Bikubi had sat next to her with a clenched fist when she spoke to her parents who were in Paris.
"My mother didn't even understand anything I was telling her," she said.
"I was told to say I had confessed to being a witch. I told her a story about clothing and a doll.
"I made it up because I was fed up with being hit."
Miss Bamu added: "They didn't tell mum that they were mistreating us. Mum asked: 'Are you hitting the children?' and Magalie said no."
She said the day before Kristy died, Mr Bikubi smashed ceramic tiles over Kristy's head.
"Kristy was tired and could not take any more, but that was not enough for Eric. He wanted him to die. They wanted his blood," she said.
The prosecution say the brother and sister and another sibling were attacked for four days at the couple's flat in Forest Gate while on holiday over Christmas in 2010.
'Begged to die'
Jurors were told Kristy became the focus of the attack and was hit with an "armoury of weapons", including sticks, pliers, a metal bar, hammer and chisel. He suffered 101 injuries.
Kristy was beaten with a stick, hammer and iron bar before drowning in a bath after begging to die, it is alleged.
Mr Bikubi has admitted manslaughter on the grounds of diminished responsibility, a plea not accepted by the prosecution. He has also admitted assaulting Kristy's siblings.
Magalie Bamu denies the murder, as well as two charges of causing actual bodily harm to her other siblings.
The case continues.