Choi Jin-ri, a South Korean singer-actress known by the stage name Sulli, was found dead at her apartment in Seoul earlier today.
The 25-year-old started her career off as a child actor and later debuted with K-pop girl group f(x) in 2009. She officially left the group in 2015 after a year's break to focus on acting.
According to Yonhap News Agency, a police official said: "Choi seemed to have lived alone in the house. It seems that she took her own life but we are also looking into other possibilities."
Police have reportedly found a memo containing her feelings, but it's said not to be a suicide note. They've said that the memo will not be made public.
Her agency, SM Entertainment, has said: "We are very sad and sorry to deliver this sad news. Sulli has left us."
"We cannot believe the current situation and it is just heart-rending ... We extend our deep condolences to the deceased," it added.
Sulli was active on social media and often spoke up for women and mental health. As a vocal user of social media, she was often the target of cyberbullying and malicious rumours. In her latest song, "Goblin", she sang about someone living with dissociative disorder.
Tributes are pouring in from fans all around the world who are praising her for how she used her voice.
Her former bandmate Amber, who was set to release new music, announced that she was putting everything on hold and thanked everyone for their thoughts.
SuperM, Super Junior, and other K-Pop groups have also cancelled upcoming events.