The former girlfriend of one of the founders of the Irish boyband Boyzone has been accused of killing her nanny and burning her body.

The French au pair, 21-year-old Sophie Lionnet, was found burned beyond recognition in the South London home of 34-year-old Sabrina Kouider, also a French citizen, on September 20.

Kouider, the mother of two children, is being questioned along with a 40-year-old Ouissem Medouni, a French-Algerian man who has been living with Kouider, reports

Kouider, who has been described as a socialite and makeup artist, has lived at the home in the Southfields neighborhood of South London since 2013.

French nanny Sophie Lionnet. Credit: Facebook

French nanny Sophie Lionnet. Credit: Facebook

She has a six-year-old son with Boyzone founder Mark Walton and a three-year-old girl with another man.

Walton is now an A&R music executive in Los Angeles and also serves as a judge on Vietnam’s version of American Idol.

A neighbor told the Daily Mail that her child thought Kouider was having a barbecue.

She said: “My young son called out, ‘If you are having a barbecue, are we allowed to come?’ I told him, ‘No, that’s not a barbecue, that’s a bad smell.’ I thought they may be burning leaves.”

A local store-owner, Sunny Patel, told the Daily Telegraph that Lionnet had not been seen since August.

Mark Walton, one of the founders of Irish boy band Boyzone. Credit: Facebook

Mark Walton, one of the founders of Irish boy band Boyzone. Credit: Facebook

He said: “I have not seen the nanny since late August. She used to come in with kids twice a day to buy them sweets. She loved about 13 but was actually in her early 20s. A very polite, pleasant girl. She was French. The family was also French. The nanny has lived her for at least 20 months, she was here last Christmas…

“Last night I saw plumes of smoke coming from the garden – lots of smoke, not much flames – but just thought it was a garden fire. Then … we were told that the man was arrested and then his wife.”

Lionnet, a native of Troyes in northern France, was reportedly only paid $63 a month. Because Kouider lived a busy social life, the au pair was reportedly forced to work long hours.  Lionnet had recently contacted relatives in France to arrange to move back home.