Couple found guilty of murdering French nanny in trial 'stranger than fiction'

Sabrina Kouider, 35, and Ouissem Medouni, 40, brutally murdered Sophie Lionnet (centre). (PA)

A delusional couple have been found guilty of killing their French nanny over a bizarre obsession with an ex-Boyzone popstar.

Sabrina Kouider, 35, and Ouissem Medouni, 40, of Wimbledon, south-west London, built a warped fantasy around music mogul Mark Walton and accused Sophie Lionnet of being in league with him.

An Old Bailey jury found both of them guilty of the murder following a two-month trial that was described as stranger than fiction.

Kouider collapsed in tears as the jury foreman returned the verdicts, while Medouni hung his head.

Miss Lionnet’s mother Catherine Devallonne also wept as Judge Nicholas Hilliard QC said he was sure the allegations against her daughter had “no truth whatsoever”.

In the weeks leading up to her death in September last year, the couple beat, starved and tortured the shy 21-year-old au pair by dunking her head into water until she confessed.

A court sketch of Ouissem Medouni (L) and Sabrina Kouider (R) during their trial at The Old Bailey last month. ( Julia Quenzler/SWNS)

After the pair killed their nanny, they threw her body on a bonfire in the garden as they barbecued chicken nearby.

When neighbours called firefighters with reports of ‘pungent-smelling smoke’, Medouni tried to pass off the charred remains as a sheep.

The defendants later admitted disposing of her body but denied Miss Lionnet’s murder, blaming each other for her death.

Prosecutor Richard Horwell QC told jurors that neither were prepared to admit the truth – that they killed her out of ‘revenge and punishment’.

He said their ‘unhealthy, myopic, all-consuming and groundless’ obsession with Mr Walton had deprived them of reason and turned their nanny into ‘something less than human’.

The court heard how fashion designer Kouider was fixated with her ex-boyfriend Mr Walton and would regularly attempt to tarnish his name on social media. 

As well as a receiving a caution for branding him a paedophile on a fake Facebook profile, Kouider also accused him of sexually abusing a cat, using black magic and hiring a helicopter to spy on her.

Giving evidence, LA-based Mr Walton said he had been ‘in love’ with Kouider but she would ‘flip’ and go ‘crazy’ for no reason.

Another ex-boyfriend Anthony Francois described her as a ‘lunatic, fickle and unstable’.

The judge is expected to sentence the pair on June 26 at the Old Bailey.