Socialite Tara Palmer-Tomkinson has been found dead aged 45.
A former Sunday Times columnist, reality TV star, and goddaughter of Prince Charles had received treatment in 2016 for a non-malignant brain tumour.
Officers were called to her flat in Bramham Gardens, South Kensington, at 13:40 GMT. A woman in her 40s was found dead at the scene, the Met Police said.
The death is being treated as unexplained.
Her next of kin and the coroner have been informed, police said.
The Prince of Wales and the Duchess of Cornwall released a statement in which they said they were “deeply saddened and our thoughts are so much with the family”, following the death of their close friend.
She rose to fame in the 1990s as a hard-partying “it girl” and put her names to several columns chronicling her glamorous lifestyle.
Later in her career she appeared on reality TV series I’m A Celebrity… Get Me Out Of Here! in 2002, as well as several other TV shows.