Social media giants have been told by the Health Secretary to purge their sites of self-harm and suicide material, or face legislation.Matt Hancock, Secretary of State for Health and Social Care, has this weekend written to social media bosses warning them that action is “urgently” needed to ensure they do not breach the policies of internet providers.In the letter, Mr Hancock expresses his growing concern over harmful content online, and states it is “appalling” how easy it is to access content that “leads to self harm and promotes suicide”.The letter, sent to corporate leaders at Facebook, Instagram, Twitter, Snapchat, Pinterest, Google and Apple, comes just days after father Ian Russell spoke out about how Instagram “helped” to kill his 14-year-old daughter, Molly.In 2017, Molly was found dead in her bedroom after showing “no obvious signs” of mental health issues, but her family later found she had been looking at material on social media linked to anxiety, depression, self-harm and suicide.Mr Hancock wrote in his letter: “Like any parent, I was horrified to learn of 14-year-old Molly Russell, who tragically took her own life.“The grief Molly’s parents feel is something no-one should have to experience. Every suicide is a preventable death, including Molly’s.”He continued: “It is appalling how easy it still is to access this content online and I am in no doubt about the harm this material can cause, especially for young people. “It is time for internet and social media providers to step up and purge this content once and for all.“I want to work with internet and social media providers to ensure the action is as effective as possible. “However, let me be clear that we will introduce new legislation where needed.”Mr Hancock ends his letter writing: “I look forward to working with you with the urgency this agenda needs.” Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.