SEOUL (THE KOREA HERALD/ASIA NEWS NETWORK) - The untimely death of K-pop group SHINee's lead vocalist Kim Jong Hyun came just a week after he wrapped up his solo concerts, a testament to his successful career that extended beyond the boy band SHINee.

Born on April 8, 1990, the singer, better known as Jonghyun, was picked up by talent scouts of S.M. Entertainment in 2005 during a singing contest.

After three years of training at the talent agency, he debuted in 2008 as a member of the five-piece boy band SHINee with the EP Replay.

Jonghyun stood out as the main vocalist of the group, captivating fans with his powerful voice and dancing ability. He demonstrated his skills outside the band as well, such as through S.M.'s project group S.M. The Ballad.

In 2015, he launched his solo career with the EP Base, followed by his first studio album She Is the following year.

Jonghyun was successful as a solo artist. He received the bonsang award at the 2016 Golden Disk and was nominated for the best male artist award at the 2016 Mnet Asian Music Awards.

The singer was also recognised for his songwriting, which began with the lyrics for SHINee's hit song Juliet. He wrote the lyrics and melodies for most of the songs in his solo career.

The prolific artist released the special album Winter Wonderland in January, followed by the compilation album Story Op.1 in September.

Jonghyun was a radio DJ as well, hosting a show on MBC radio from 2014 to April this year.

His death came as a surprise, as he had just wrapped up solo concerts from Dec 9 to 10.

SHINee was expected to hold a Japan concert in February 2018. Jonghyun was also expected to appear on JTBC's Night Goblin that was to be aired on Sunday.

The singer had also posted a final photo on his Instagram account on Nov 20. The photo had showed lyrics from a song by the group Dear Cloud, which read "persistent scars and sighs of exhaustion, will they have stopped?"

Fans have speculated that the lyrics may have been indications of his imminent death.

Police said on Monday they received a telephone call from Jonghyun's sister at 4.42pm Korea time, saying she thought he may have attempted suicide.

His final words to his sister: "It's been difficult for me. Let me go."