A “sadistic” couple who tortured and drowned a teenage boy after accusing him of witchcraft were jailed for a total of at least 55 years today.

Magalie Bamu, 29, attacked her 15-year-old brother Kristy Bamu with pliers and a metal pole, while her fiancee Eric Bikubi, 28, used knives, wooden planks and a hammer.

The pair also inflicted beatings on Kristy’s sister Kelly, 20, and an 11-year-old sister, who cannot be named, after accusing them of sorcery.

Kristy suffered 130 separate injuries after he was subjected to “torture of quite brutal and savage proportions”, the Old Bailey heard.

His face and head were covered in cuts, his teeth had been smashed out and ceramic floor tiles had been broken over his head when he was discovered in his attackers’ blood-soaked flat on Christmas Day 2010.

Part of his ear had been torn off with the pliers and he had been forced to eat a metal screw.

Bikubi admitted the killing, but claimed he was only guilty of manslaughter because he was suffering from brain damage that could have caused delusions and hallucinations, while his lover denied any part in the attacks.

But both were found guilty of murder following a two-month-long trial.

Bikubi had already admitted assault occasioning actual bodily harm against Kristy’s sister Kelly and the 11-year-old sister, while Bamu was convicted of identical charges.

They were given life sentences today, with Bikubi handed a minimum term of 30 years and Bamu 25 years, for what Judge David Paget QC described as a “sadistic” killing that “surpassed belief”.