A lawyer for the Flack family said that she took her own life on Saturday. Her body was found at her home in east London.
The tragic news has prompted questions about the pressures faced by TV celebrities and about the decision to press ahead with her prosecution for an alleged assault on her boyfriend Lewis Burton.
In a statement released on Saturday night, Flack’s management company criticised the Crown Prosecution Service (CPS) for pressing ahead with what it called her "show trial" even after her boyfriend said he did not support it.
The CPS responded: "Given the tragic circumstances, we will not comment on the specifics of this case at this stage."
Burton paid tribute on Sunday morning, posting on Instagram that his “heart is broken” and that “we had something so special”.
His was among a flood of tributes for the star.
Laura Whitmore, who replaced her as Love Island host after her arrest, posted a picture of the pair on Twitter and wrote: "I'm trying to find the words but I can't."
I’m trying to find the words but I can’t 💔 pic.twitter.com/FY3ppLzqsA— Laura Whitmore (@thewhitmore)February 15, 2020
Comedian Iain Stirling, who provides voiceover work for Love Island, also paid tribute.
“Today my friend slow motion walked into heaven. I will miss her always,” he wrote alongside a video of Flack performing on Strictly Come Dancing.
Today my friend slow motion walked into heaven. I will miss her always. Thank you for everything x
pic.twitter.com/gykAn9YE3U— Iain Stirling (@IainDoesJokes)February 15, 2020
Strictly remembered her as someone who had "an infectious energy and passion for dance".
She took part in the BBC One show in 2014 and emerged the winner alongside her professional partner Pasha Kovalev.
A statement posted on the official Strictly Twitter account said: "The entire Strictly Come Dancing family are heartbroken to hear this incredibly sad news.
"Caroline had an infectious energy and passion for dance, she shone brightly in the Strictly ballroom every week and became an incredible champion.
"Words cannot express our sadness, she was simply one of a kind. We are sending our love to all her family and friends during this difficult time".
One of the dancing show's hosts, Tess Daly, also shared a tribute, tweeting: "Absolutely shocked and devastated at this tragic news. Rest in peace Caroline you beautiful girl. My heart goes out to your family and loved ones at this time XXXX".
Absolutely shocked and devastated at this tragic news. Rest in peace Caroline you beautiful girl. My heart goes out to your family and loved ones at this time XXXX— Tess Daly (@TessDaly)February 15, 2020
Co-host Claudia Winkleman wrote: "Such heartbreaking news."
Such heartbreaking news. Sending so much love to Caroline's family and friends. XXX— Claudia Winkleman (@ClaudiaWinkle)February 15, 2020
Strictly judge Bruno Tonioli tweeted: "Just can't believe it... Always so much fun to be around, such sad news. RIP."
Eamonn Holmes said he was "shocked beyond belief" and questioned whether there would be "repercussions" for Love Island.
Caroline Flack .... Dear God.
Shocked beyond belief. May she have found peace . #Rip
Has to be repercussions for Love Island now surely ?— Eamonn Holmes (@EamonnHolmes)February 15, 2020
Kady McDermott, who appeared in the show's second series, said: "Devastated to hear the news about Caroline Flack.
"Caroline was nothing but kind to me and that's how I will always remember her.
"Saddens me so much when people think the only way out is death. My prayers and thoughts go out to Caroline's friends and family."
When I went through a tough time a while back in the press Caroline reached out to me and I’ll always remember that. Just completely sick to my stomach over what’s happened. Absolute tragedy 💔— Kady Mcdermott (@kadymcdermottx)February 15, 2020
TV presenter Jonathan Ross tweeted: "I had been in touch with her recently and had hoped she was doing better. She was talented and smart and likeable and she will he missed. It's awful."
TV duo Ant McPartlin and Declan Donnelly shared a tribute on their joint Twitter account, writing: "It is beyond sad. Beyond words. So tragic. Our thoughts and prayers are with her family. Rest In Peace Caroline XX."
We are both devastated to hear the news about Caroline Flack. It is beyond sad. Beyond words. So tragic. Our thoughts and prayers are with her family.
Rest In Peace Caroline
XX— antanddec (@antanddec)February 15, 2020
Her friend Dawn O'Porter posted a string of messages on Twitter, saying: "At some point I will find my words, and I will write the tribute she deserves. My dear friend. I'm lost."
And her friend Kirsty Gallagher added: "You were my little sister, 20 years of friendship. We grew up together in this industry. Fun, kind and brilliant in every way. You don’t know how much we’ll miss you."
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