The 30-year-old singer, whose real name is Jung Ji-hoon, has come under fire after paparazzi pictures showed him on dates with popular actress Kim Tae-hee several times last month in what was seen as a violation of regulations.

The K-pop star has reportedly received 71 days of vacation last year, while a regular enlisted soldier is supposed to get only 28 days of vacation during their two years of compulsory military service.

The media revelations touched off criticisms that celebrities who serve as "entertainment soldiers"receive special treatment, prompting the Defense Ministry to look into the matter. "It is true that corporal Jung Ji-hoon had private contacts on his way back to the barracks, which constitutes as a violation of military rules,"ministry spokesman Kim Min-seok said in a press briefing.

All able-bodied South Korean men over 20 are required to serve in the military for about two years.

The bulky "Rainism" singer, who also starred in Hollywood movies "Speed Racer" and "Ninja Assassin," is one of the most successful K-pop stars with a massive following across Asia.

He will be discharged in July.