The mother of a teenage girl who committed suicide has said more action needs to be taken to stop vulnerable people viewing self-harm or 'suicide blogs' online.
Sarah Wilson, whose 15-year-old daughter Tallulah died after being hit by a train, said she felt she was unable to help her daughter after she had fallen into the "clutches of a toxic digital world".
An inquest into the teenager's death said Tallulah, from West Hampstead, north west London, died after she had an argument with her mother when she deleted her Tumblr account. The teenager died six days later on 14 October, 2012.
Tallulah was described as an avid user of the social media site and would post pictures of her self-harming on the blogging platform. The jury at the inquest said the Tumblr account was "very important" to Tallulah and provided her with a "medium to express herself over which she had total control".
St Pancreas coroner's court was told Tallulah also created a cocaine-taking alter ego while using the website.
Her mother told the court before her daughter's death, Tallulah became so obsessed with the self-harm and suicide blogs that she had "entered a world where the lines between fantasy and reality became blurred".
Wilson also expressed her disbelief about how easy or was for children to access this material and said more needs to be done to protect them from the most "insidious aspects of the internet".
Wilson said: "Our lives will never be the same without Tallulah. We have lost someone more precious than words could ever say – a beautiful, loving and talented shining star has been stolen from our skies.
"Her sisters and I did everything we could to keep her safe, but she had fallen into a world of nightmares. She was in the clutches of a toxic digital world where in the final few weeks we could no longer reach her."
She added: "I believe the likes of Tumblr should do more to protect other vulnerable young people from the insidious aspects of the internet; they need to take an active role in policing and swiftly removing unsuitable material as some sites already do.
"I appeal to big brands to withdraw their advertising from those sites who continue to host inappropriate self-harming and suicide-promoting blogs to stop this poison spreading."
Tumblr said it is committed to improving its ability to act on self-harm content.
A spokeswoman for Tumblr said: "Tallulah Wilson and her family are in the thoughts of Tumblr and its employees.
"Issues of depression and self-harm are extremely challenging, particularly in online environments that encourage self-expression.
"Tumblr has policies to address the most harmful of this content, and we have systems in place to direct users to appropriate resources for getting whatever help they may need.
"We are [also] committed to keeping Tumblr a positive, supportive environment for those individuals dealing with issues of depression and self-harm."
For confidential support call the Samaritans on 08457 90 90 90, visit a local Samaritans branch or see Samaritans.org.