Kim Jong-Hyun, who sang and performed as part of the chart-topping band SHINee, committed suicide, according to reports in the Korean media.
A statement from Gangnam Police confirmed that the talented musician's sister called officers with concerns that Kim was threatening to take his own life.
"On December 18, 2017 at 4:42PM Jonghyun's older sister reported to Police that her brother was about to commit suicide," said the statement.
"We went to his residence in Chungdam and discovered that he had attempted to commit suicide."
The statement added: "Emergency responders were with us at the time so we rushed him to the Konkuk University Hospital in a state of cardiac arrest."
His cause of death is said to be carbon monoxide poisoning, which could have been caused by breathing in fumes.
It's being reported by Korean news sites that Jonghyun left a suicide note, which his sister may have read.
Just three days ago, Jonghyun was reportedly under fire from trolls belonging to an ultra-conservative group.
#RIPJONGHYUN #STAYSTRONGSHAWOL
WE WILL NEVER FORGET ABOUT YOU