North Korean leader Kim Jong Un is alive, South Korean intelligence have claimed, following days of rumours that he had died or is seriously unwell after a botched surgery.

“Our government position is firm,” Moon Chung-in, South Korean President Moon Jae-in’s main foreign policy adviser, told CNN.

“Kim Jong Un is alive and well. He has been staying in the Wonsan area since April 13. No suspicious movements have so far been detected.”

Kim variously reported as being ill and taken care of

Kim had allegedly undergone a cardiovascular procedure, it was rumoured, which was due to “excessive smoking, obesity, and overwork" and he was supposedly “in grave danger".

He is reportedly being looked after by a small medical team while recovering.

China had reportedly sent a team of doctors and officials to North Korea on April 23 to provide advice on Kim, but this development was also unconfirmed.

Personal train parked at luxury compound

However, satellite images reportedly showed Kim’s personal train parked at a station near his luxury compound on the country’s eastern coast for several days.

Images reviewed by 38 North, a Washington-based North Korea monitoring project, showed that the train had been parked at the “leadership station” in Wonsan since at least April 21.

38 North said the 250m train was not present on April 15, but was seen on both April 21 and 23.

The station is reserved for the use of the Kim family, it added.

“The train’s presence does not prove the whereabouts of the North Korean leader or indicate anything about his health but it does lend weight to reports that Kim is staying at an elite area on the country’s eastern coast,” the 38 North report said.

U.S. said no sign of unusual activity

Newsweek reported that United States intelligence has seen no sign of unusual military activity in the country, but are continuing to monitor the situation closely.

Ex-North Koreans disagree about rumours

According to Korea Times, Ji Seong-ho, a defector who won a seat in the national assembly elections in South Korea just a week ago, claimed a source inside North Korea had confirmed with him that Kim was “seriously ill” and that the country was in the grip of a succession struggle.

However, Thae Yong-ho, the most senior North Korean diplomat to have defected, said it was impossible to speculate about the state of Kim’s health.

Thae, a former North Korean deputy ambassador to the United Kingdom, who also won a national assembly seat in the south, said: “The supreme leader’s whereabouts are protected with intense secrecy, so very few people know these details. Considering the gravity of the situation, it is impossible for news of his poor health to spread to the border with China.”

The age of the North Korea leader is also shrouded in mystery.

It has been frequently reported the past week that he is believed to be 36 years old though.

Top photo via KCNA