New Zealand-born media personality Charlotte Dawson has been found dead in her apartment in the inner Sydney suburb of Woolloomooloo.
Police say there are no suspicious circumstances.
Charlotte Dawson. Photo: AAP / DAN HIMBRECHTS
The former model, 47, had a history with depression.
Ms Dawson was hospitalised in late 2102 after being bombarded with Twitter messages.
She was a vocal anti-bullying campaigner and until recently had been campaigning for cancer resources.
A friend of Ms Dawson and mental health advocate, comedian Mike King, hopes her death will make people see the seriousness of depression.
He says she was very misunderstood by New Zealanders and describes her as a beautiful person who will be sadly missed.
"Hopefully this will be a tipping point for the way the media, the way the internet trolls; the way the doubters look at this thing and finally, finally face up and see the seriousness of what it's like to live with depression,"
Prime Minister John Key has tweeted that he is shocked and saddened to learn of her death.
Ms Dawson left New Zealand at the age of 16.
Other tributes have been flowing for Ms Dawson, with shocked social media users saying the news of her death is a reminder to always be kind.
Until recently, Ms Dawson was a judge on the Foxtel reality television series, Australia's Next Top Model.
Ms Dawson often appeared on morning and breakfast television shows, last appearing on the Nine Network's Morning Show on Friday.
She was once married to troubled Australian Olympic swimmer Scott Miller, who pleaded not guilty to drugs charges in Sydney last month.
A post-mortem will be carried out.
