Tara Palmer-Tomkinson found dead at her home in London
Tara Palmer Tomkinson has been found dead in her London flat.
The 45-year-old former It girl had recently revealed a secret year-long battle with a brain tumour.
Officers were called to Palmer Tomkinson's home on Wednesday afternoon by the London Ambulance Service.
It is understood that her death is being treated as unexplained - but not suspicious.
A spokesman for the Metropolitan Police said: "Police were called by London Ambulance Service at approximately 13:40hrs on Wednesday February 8 to an address in Bramham Gardens, SW5.
"A woman, aged in her 40s, was pronounced dead at the scene.
"At this early stage, the death is being treated as unexplained.
"We are not treating this death as suspicious. The coroner has been informed and the next of kin has been informed."
The Prince of Wales and the Duchess of Cornwall have said they are "deeply saddened and our thoughts are so much with the family."
Last November, the socialite said she had received treatment for the non-malignant growth in her pituitary gland since January 2016 and that it had been cleared.
She was a regular on the London party scene in the 1990s and 2000s and made headlines for her social life, frequently appearing in the pages of both society and celebrity magazines.
During her years in the spotlight, she was a newspaper columnist and television personality, but also battled a high-profile cocaine addiction.
Despite being famed for her hard partying and exhibitionist streak, Palmer-Tomkinson and her family were close friends of the Royal Family and she attended the wedding of the Duke and Duchess of Cambridge in 2011.
She appeared on reality TV series I'm A Celebrity ... Get Me Out Of Here! in 2002 and finished second behind DJ Tony Blackburn.
Darren Day, who appeared alongside her in the jungle, said: "I'm so sad to hear that Tara Palmer-Tomkinson has passed away. Thoughts and love to her family RIP Tara x."
She also made appearances on other TV shows, including celebrity specials of Blind Date and A Place In The Sun.
In 2014, she said she had become a recluse after suffering a nervous breakdown and spoke about her battle with drug addiction on ITV show Jeremy Kyle: The Celebrity Specials.
She broke down in tears as she recalled the night she nearly died from an overdose during her battle with cocaine addiction.
She eventually quit drugs following a 35-day stint in an Arizona rehab clinic.
In an interview last year, she said: "I definitely have regrets. I wish I had never touched half the stuff.
"But in the same way, I'm not going to sit there and feel ashamed for what I did, because I have had a life!
"I might be 44, but I was at so many different parties in so many different countries, I haven't slept for 20 years!"
Socialite and reality TV star Tamara Beckwith, one of her friends, said in a statement: "The terribly sad news of my old friend Tara PT's passing has come as quite a shock.
"She was a shining light and I have nothing but very fond memories of the times we had together. She was most definitely one of life's true characters.
"My thoughts are naturally with her family."
Blue singer and soap actor Duncan James, a close friend, tweeted: "Heartbroken and numb I have lost one of my oldest and dearest friends.
"I'm going to miss ur laughter the most."
Singer Alexandra Burke wrote on Twitter: "What a sad day. RIP TPT. I will never forget how warm and loving you were every time I met you.
"I'm in so much shock that Tara has passed away. So young. So tragic. My prayers and thoughts are with her and the family at this sad time."
Former Westlife star Brian McFadden called her a "real character" and added that she "will be sadly missed".