The 18-year-old sister of the One Direction star tragically passed away in March at her fourth-floor studio apartment in Earls Court, West London, after collapsing from a suspected heart attack.
And at an inquest hearing in London on Wednesday (11.09.19), a coroner recorded a misadventure verdict, and ruled she had accidentally overdosed on a mixture of cocaine, an anxiety drug and painkillers.
Coroner Dr Shirley Radcliffe said: "It was a perfect storm, the OxyCodone, the alpraxolam and cocaine. I find no evidence this was a deliberate act to end her life."
At the time of her death, spokespeople for the Met Police and the London Ambulance Service both confirmed details of the tragedy.
The Met Police source said: "Police were called by the London Ambulance Service at 12.52pm to a residential address in SW5."
Whilst the London Ambulance Service added: "We were called at 12.51pm. We sent two ambulance crews, a single responder in a car and an advanced paramedic to the scene. Sadly, despite efforts of our medics, a person died."
Meanwhile, a family source previously claimed Louis - who also lost his mother Johannah Deakin in 2016 after a battle with cancer - was "devastated and distraught" by the tragic news.
They said: "Félicité was an absolutely adored young woman who was loved by Louis and her whole family. They are all totally devastated, as you can imagine. She had so many friends and was such a positive happy person.
"It's a massive loss to the world. She was a loveable, caring, bright, passionate, popular and beautiful young lady."
The 'Two of Us' singer broke his silence on Félicité's passing on social media in April, when he thanked fans for the kind messages they had sent his family.
He tweeted at the time: "Just wanted to thank everyone for their lovely words over the past couple of weeks. Back in the studio today to vocal something I wrote a few months ago. Sending you all loads of love x (sic)"