Undisclosed video of teen Kim Hyun-joong to air on cable

Never-before-seen videos of SS501 member Kim Hyun-joong from his teen days will be aired on MBC's cable channel on Friday.

MBC every1 said in a press release on Wednesday that its documentary program "Star: The Secret" will feature the hit idol group member, broadcasting clips of Kim from his rock band days in 2003 as well as pre-debut photographs.

The video will show the singer, then 17, playing the bass as a member of his church's rock band. The group is said to have been invited to perform at numerous events including rock festivals and school events in the Songpa district of Seoul.

The show will also reveal undisclosed photographs of Kim from his school days and his first-ever photoshoot ahead of his debut.

He is now the leader of five-member boy band SS501 which has been popular since their debut in 2005. His popularity surged this year after appearing in hit TV series "Boys Over Flowers" alongside actors Goo Joon-pyo, Kim Bum and Kim Jun.

The episode of "Star" featuring Kim will be aired at midnight on Friday.