Kim Jong-Hyun, the lead singer of one of South Korea's top K-pop boy bands Shinee, died on Monday after being found unconscious at a rented studio apartment in Seoul on Monday evening, the Yonhap News Agency reported, quoting police.

The 27-year-old had faced a barrage of tweets and social media messages for his support of LGBT issues in socially conservative South Korea.

He came under attack in 2013 after publicly supporting a transgender student who had been posting handwritten messages around the grounds of Korea University criticising the social suppression of LGBT people.

He killed himself by carbon monoxide poisoning after sending a message to his sister saying “ell everyone I've had a hard time,” according to local media reports.