He is the latest in a string of deaths by young Korean performers, some by suicide.
In 2011, Choi was the runner-up on Koreas Got Talent, which aired on tvN.
He performed Ennio Morricones Nella Fantasia, missing top honors on the program by just 280 votes.
Choi Sung-bongBong Bong Company
The YouTube clip of his performance was viewed more than 21 million times.
He went on to score a recording contract and published a memoir.
The claim was later found to be a hoax, and Choi vowed to make restitution to his supporters.
The note claimed all donations were returned.
