Seoul, July 30 (DPA) North Korean leader Kim Jong Il is receiving dialysis treatment due to his chronic renal failure, a North Korean watcher said Thursday here.

Ha Tae Gyung — who runs South Korea-based Open Radio for North Korea, which broadcasts into the totalitarian state — said Kim’s treatments began before his country conducted a nuclear test May 25.

Ha said he received the information from multiple sources in North Korea who he did not name.

Kim’s health is a closely guarded secret in North Korea, but he is believed to suffer from diabetes and heart disease and South Korean intelligence said he had a stroke in August.

His health is closely watched internationally because Kim, 67, has not publicly named a successor. Some North Korea watchers said, however, that his third and youngest son, Jong Un, who is in his mid-20s, is being groomed to take over from his father.

Observers said Kim’s worsening health and his wish to be succeeded by his son prompted him, in a show of strength, to conduct the nuclear test, North Korea’s second after an initial one in 2006, as well as a series of missile launches, including a long-range rocket in April – all of which were internationally condemned.

“What went wrong with North Korea?” asked Lee Jo Won, a professor at South Korea’s Chung-Ang University. “Why should it fire off a barrage of missiles and conduct a nuclear test without gaining anything from them in return?”

Ha said Kim is believed to be ill enough to increase his fear of losing his grip on North Korea, where he is referred to as “Dear Leader”.

Patients are put on dialysis when their kidneys, which remove waste from the blood, are not functioning properly. Dialysis machines are then used to cleanse the blood.

“Kim’s blood cannot carry protein and nutrients into every corner of his body, causing his hair to thin, a loss in weight and his face skin to sag,” Ha said. “His eyesight might have also weakened.”

Ha’s description fit the television appearance Kim made July 8 at a memorial service for his father, Kim Il Sung, North Korea’s first leader. He was thin, walked with a slight limp and had a slightly lopsided mouth.