TV star and former model Charlotte Dawson has been found dead at her Woolloomooloo apartment.
The New Zealand-born celebrity, 47, had a history of depression and had been admitted to hospital in 2012 after vicious social media attacks following her criticism of cyber bullying by Twitter trolls.
Her close friend and fellow Australia's Next Top Model judge Alex Perry led the tributes.
Friends in Australia and around the world took to social media to express their grief.
Heartbroken to hear news that Charlotte Dawson has died. In shock right now. U will always have a special place in our hearts Charlotte. RIP
I am devastated by the news that @MsCharlotteD has taken her life in Sydney. She was a mentor, a friend and beautiful human. #RIPCharlotte
We may not have always seen eye to eye, but I'm very sad and feel very sick about the death of Charlotte Dawson. May you find peace now.
So sad to hear the news of Charlotte Dawson's passing. My thoughts are with her family and friends at this difficult time #RIPCharlotte
RIP Charlotte Dawson . I'm devastated such an amazing woman & kind soul. Heartbreaking !
So tragic. Life is so precious. RIP Charlotte ❤️ May heaven be a happier place for you x
To the beautiful Charlotte Dawson. Your infectious personality will be sorely missed #RIPCharlotte
Deeply saddened by the loss of our friend Charlotte Dawson. Our thoughts go out to her loved ones.
A wave of sadness has washed over me this afternoon. To anyone suffering alone please call lifeline 131114. #RIPCharlotte
Sad, sad, sad news about the glorious Charlotte Dawson... Mental illness is a dirty, black dog and she did so much to help countless people
I hope Charlotte's friends know they did love her enough...sometimes the pain is too deep. Such a sad day. #Lifeline131114
I have just heard the incredibly devastating news about Charlotte Dawson. I'm in shock. May this beautiful lady Rest in Peace.
My whole family is devastated at death of Charlotte. We shared a common love of basketball & Sydney Kings.She was always so kind to my girls
Charley D...Just don't understand. There's not enough kind souls as it is. Rest in peace.
New Zealand Prime Minister John Key tweeted a tribute.
Shocked and saddened to hear of Charlotte Dawson’s death.
Another close friend, news.com.au Editor-at-Large Melissa Hoyer remembered a happier moment.
Hoyer left a beautiful tribute on Twitter.
Troubled. Funny. Opinionated. Wry. Clever. Beautiful. Passionate. Wanting to b loved. That's the Charlotte Dawson many of us knew. Rest now.
Many were quick to link Dawson's death to the abuse she had suffered at the hands of anonymous Twitter trolls.
I hope all of the social media trolls reevaluate their lives and actions today. #RIPCharlotte
Twitter trolls take note - your words affect people much more than you think #RIPCharlotte
If you, or someone you know, is living with depression and anxiety @beyondblue can help http://t.co/47x81N1VxU #RIPCharlotte #mentalhealth
Just so sick of these faceless trolls- Big difference between having an opinion and straight out cruelty, bullying and hate #ripcharlotte
Bullying is not cool ... it kills! #RIPCharlotte