Updated

North Korean leader Kim Jong Un was shown limping on state television Tuesday as he attended a memorial event commemorating the 20th anniversary of the death of North Korea's founder.

The footage showed Kim walking with a slight, but visible limp as he assumed his position of honor prior to the ceremony honoring his grandfather, Kim Il Sung, at a stadium in Pyongyang. He limped again as he left the room when the event was over.

It is unusual for the North's state-run media to display images of the country's leaders that do not depict them as being in peak physical form. For example, in the months before the death of Kim Il Sung in 1994, state media were forbidden to photograph him from angles that showed an inoperable growth that had developed on the side of his neck.

The footage is likely to increase speculation about the state of Kim Jong Un's health, particularly in South Korea, where the media has devoted much coverage to Kim's reported weight gain and smoking habit. He is also rumored to have recently undergone plastic surgery to make him bear more of a resemblance to Kim Il-sung.

The South Korean newspaper Chosun Ilbo reported that Kim wore a "gloomy expression throughout [the ceremony] and applauded feebly." A government official speculated to the paper that Kim may have suffered a sprained ankle or sustained back or knee problems during a recent tour of military bases.

Researcher Park Hyung-joong at the Korea Institute for National Unification tells the paper that if the limp were a sign of a serious health issue, it is unlikely that Kim would have been shown walking.

Click to see the footage.

Click for more from The Chosun Ilbo.

The Associated Press contributed to this report.