Charlotte Dawson’s death has put the spotlight on cyber bullying. Mental health advocate Kate Carnell, CEO of BeyondBlue, has hit out at social media site Twitter for failing to respond to bullying attacks on the former model.

The New Zealand-born Australian television personality was found dead in her Wolloomooloo, NSW home on Saturday, with reports confirming that she committed suicide. She was 47.

According to various reports, her critics on social media were a big factor in her battle with depression, and therefore have contributed in her death. Dawson had been warring with Twitter “trolls” for years. She had been a favourite target of people hiding behind their username online, often receiving spiteful messages that mocked her battle with depression.

In 2012, she was hospitalised after getting mean messages online that triggered her anxiety attack.

“When I got home late at night [the hate tweeters] started sending child pornography, mutilated bodies and I got hundreds and hundreds of messages asking me to kill myself,” she had recounted then.

“I ignored it and went to sleep and I woke up a couple of hours later to check the feed and I could feel the adrenalin just started pumping and I just had a massive, massive anxiety attack.”

In 2013, Facebook, Google, Yahoo, and Microsoft signed up to a federal government scheme, which handles complaints about hateful materials on their sites. Twitter did not sign up to scheme’s guidelines.

Ms Carnell, former chief minister of the Australian Capital Territory (ACT) and the CEO of BeyondBlue, has lashed out at Twitter for its lack of response to people who are using the site to bully others.

“Twitter hasn’t signed up. That’s not good enough,” she was quoted by the Sydney Morning Herald as saying.

“Yes, governments have a role, but so do major social media sites. Facebook have been active in this area. There’s lots more work that people like Twitter need to do.”

She added, “We need to have real penalties in place for people who engage in bullying. We have to get mechanisms in place. This is a form of violence.”

BeyondBlue is an organisation that raises awareness to reduce the impact of depression and anxiety in the community.