A woman accused of torturing her brother Kristy Bamu to death because she suspected he was a witch sobbed in the Old Bailey witness box as she insisted: “I didn’t have a choice.”

Magalie Bamu, 28, claimed boyfriend Eric Bikubi threatened her with a plank of wood and ordered her to attack the 15-year-old.

When she refused, her furious partner hit him even harder, she said.

Gesturing towards Bikubi, she added: “None of us had a choice because of him.”

Kristy and two sisters were forced to stand in a corner of the flat in Manor Park while Bikubi punched them and told a brother to do the same, she said.

Later Bikubi used weapons including a weightlifting bar, a curtain pole, pliers and a hammer, as well as inserting a lightbulb into Kristy’s mouth, she said.

Kristy’s brothers were also ordered to hold him down while Bikubi broke ceramic floor tiles over his head before he drowned the teenager in the bath.

Bamu said he had lied to her about working in a clothes shop when he had in fact been signing on.

He was also having an affair with another woman.

“I don’t think I know Eric at all”, she said.

Later, she said she was called into the bathroom. When she entered, she claimed the water in the bath was already up above Kristy’s nose.

“He was just lying there,” she told the court.

“I was saying ‘Eric, you need to call the ambulance, he’s not moving’. But Eric said he was pretending.”

Bamu eventually managed to make a 999 call from her mobile phone, the court heard.