But Choi Sung-bong's powerful baritone voice and his inspirational life story have now pulled at the heart strings of millions around the world thanks to the Internet, a story rivalling that of Susan Boyle.

It was during first round of the TV talent competition "Korea's Got Talent" that 21-year-old Choi explained how he started singing seriously.

"When I sold chewing gums at a night club, I saw a man singing a vocal music. Normally they sang popular songs cheerfully at night clubs, but he sang a vocal music seriously, which impressed me. From that time on, I liked vocal music," said Choi.

Much of Choi's incredible life story was revealed on the show. He hesitated when asked about his leaving the "family" portion of the application blank, before revealing in a soft voice that he'd been left in an orphanage at age three.

"I was left at an orphanage at the age of three. I ran away from the orphanage at five after I was beaten (by the people there)," Choi said.

He added that he lived on the streets in the city of Daejon, south of Seoul. He survived by selling gum and energy drinks, and sleeping "on the stairs or in public toilets."

A turning point in Choi's life came at 14, when a woman from a snack bar near a bus station in Daejon helped him enter night school. He soon passed middle and elementary school equivalency exams, and teachers discovered his talent for singing.

His attendance at art school almost came to a premature end as the young man battled to juggle lessons with the more pressing need to earn a living.

Having been accepted to audition for the talent contest, Choi's singing voice left the show's judging panel and audience in tears.

"I just wanna give Choi Sung-bong a hug," judge and actress Song Yun-ah said.

Choi explained how much he loves singing.

"(Singing is) the reason for my living, I think," he said.

While some on the Internet have questioned the authenticity of his story, the show's producer Kim Sae-jin stands by Choi.

Indeed, Choi's case was all too familiar during the height of the Asia financial crisis in the late 1990s, when authorities said thousands of children were abandoned by one or both parents. Many lived at home alone.

Many young people at a Seoul coffee shop said they were impressed with Choi's singing ability and they felt sorry for the difficult life he has waged.

"It is amazing how much he tried for his dream. And his talent is marvellous," said 35-year-old Ko Eun-jin.

"His talent should be recognized until the end - his fans should support him continuously," said 28-old Choi Im-shik.

In a country which has spawned countless carefully groomed and trained K-pop boy and girl bands which have churned out hit after hit across Asia, Choi's rise to fame is even more phenomenal than his choice of song.

Like Susan Boyle, who shot to fame when her rendition of "I Dreamed a Dream" from the hit musical "Les Miserables" on "Britain's Got Talent" went viral on the internet, so has Choi become a global phenomenon.

The video has also caught the attention of pop professionals and pundits. The likes of singing sensation Justin Bieber, who was himself discovered on YouTube in 2008, and the "Perez Hilton" celebrity gossip website are among those lauding his talents.

Choi sang Cinema Paradiso at a semi-final round of the popular talent contest and has gone onto the final which will be held on August 20.