South Korea and China have cast doubt on reports that Kim Jong Un is in "grave danger" after undergoing heart surgery.

It is difficult to verify reports about the secretive state of North Korea, as information is tightly controlled.

Daily NK, a website run mostly by North Korean defectors, said that Kim is recovering at a villa in Hyangsan County in North P'yongan province after having surgery on 12 April.

The report said Kim's health had deteriorated recently due to heavy smoking, obesity and overwork.

A source was quoted as saying: "My understanding is that he had been struggling (with cardiovascular problems) since last August but it worsened after repeated visits to (the country's sacred mountain) Mount Paektu."


CNN reported he was in "grave danger" following the surgical procedure, citing an anonymous US official.

Image: Seoul says Kim Jong Un appears to be handling North Korean affairs as usual

South Korea's Unification Ministry, which deals with inter-Korean affairs, earlier said it was investigating the reports.

Two South Korean government officials later rejected the CNN report without commenting on whether Kim had undergone surgery, and the presidential Blue House said it had detected no unusual activity in the reclusive state.

"We have no information to confirm regarding rumours about Chairman Kim Jong Un's health issue that have been reported by some media outlets. Also, no unusual developments have been detected inside North Korea," Blue House spokesman Kang Min-seok said in the statement.

And an official at the Chinese Communist Party's International Liaison Department, which deals with North Korea, told Reuters a source did not believe Kim was critically ill.

Kim, 36, was last seen in public on 11 April at a meeting of the ruling Workers' Party politburo.

But when the country celebrated the birthday of his late grandfather and state founder Kim Il Sung four days later, he was absent, raising speculation about his health.