Kim Jong-nam, who has remained elusive after the death of his father Kim Jong-il, was spotted in Beijing on Saturday.

According to news reports citing Park Seung-jun, a visiting professor at Incheon University, Kim Jong-nam was at the Beijing Capital International Airport waiting for a flight to Macao.

Kim has been based in Macao for some time, and has mostly stayed outside North Korea since he was stopped by Japanese border control in 2001 for attempting to enter the country using a forged passport. Kim is said to make periodic visits to Beijing where his first wife Shin Jong-hui lives.

According to Park, Kim appeared to have put on a significant amount of weight in comparison to older images released through the media.

Kim, who was wearing a baseball cap, was alone without anyone appearing to be aides or bodyguards, Park said.

The South Korean professor said that he spoke to Kim to confirm that he was the eldest son of Kim Jong-il.

When questioned about whether he was surprised by his father’s death, Kim responded that it was “nature.”

He refused to clarify whether he attended the funeral.

When Park asked if he will now have to look after his younger brothers he simply said “I suppose so.”

Although Kim left the question unanswered and there have been reports of Kim entering North Korea soon after Kim Jong-il’s death, experts say that it is unlikely that he attended the funeral.

According to local North Korea sources, Kim appears to have stayed in Macao as his position in relation to the new regime would make such trips difficult.

After the elder Kim died on Dec. 17, his youngest son Kim Jong-un assumed power in Pyongyang, which raised speculations about the future of his two older sons Kim Jong-nam and Kim Jong-chol.

Kim Jong-nam in particular appears to have a tenuous relationship with Pyongyang’s new supreme ruler. There have been reports that Kim Jong-un had planned to assassinate his eldest brother and that such plans were thwarted by China’s intervention.

Kim Jong-nam’s doubts about North Korea and its regime have been reported on a number of occasions, most recently through an article carried by Japan’s Tokyo Shimbun.

In the Jan. 12 article, the Tokyo Shimbun quoted Kim as saying that passing on power for the third generation was “difficult to understand with normal reasoning.”

In the interview, conducted through e-mails, Kim also voiced doubts about the ability of Kim Jong-un.

“(I have) Doubts about how the absolute power maintained for 37 years can be carried on by the young heir with only about two years (of training),” Kim was quoted as saying by the paper.

By Choi He-suk  (cheesuk@heraldcorp.com)