Rumors continue to swirl about the health of North Korean leader Kim Jong Un.

A source told a Hong Kong broadcast journalist that Kim is dead, while Japanese weekly magazine Shukan Gendai reported Friday that Kim is in a “vegetative state” following a heart operation earlier this month. Shukan Gendai cited an unnamed member of Kim’s medical team.

Kim, 36, reportedly needed a stent procedure, a surgery that requires putting a tube into a congested blood vessel to allow blood to keep flowing to the heart. 

Rumors surrounding Kim’s health started circulating after he was absent from a celebration of his grandfather’s birthday on April 15.

Kim allegedly had a heart operation on April 12 after he fell to the ground clutching his chest during a visit to the countryside earlier this month, a Chinese expert told the magazine.

The medical history of Kim may have Chinese officials concerned. Reuters reported Friday that a team of Chinese doctors and officials were dispatched to North Korea to advise on Kim's health. China and North Korea have a strong relationship, as North Korea receives 87% of its imports from China. 

Kim had been at risk for a health crisis, as he is a smoker and heavy drinker. South Korea’s spy agency claimed in 2016 that Kim had gained an enormous amount of weight because he suffers from insomnia due to assassination fears. Pictures since 2011 have shown that Kim has gained considerable weight. 

In September 2014, North Korean authorities conceded for the first time that Kim had an “uncomfortable physical condition." There have been no reports this week from North Korea state media about Kim's condition and his whereabouts.

Kim also has a family history of heart problems. Both his grandfather and father died of heart attacks at 82 years old and 69 years old, respectively. 

Kim has led the country after his father Kim Jong Il died in 2011. He has maintained his father's authoritarian rule, implementing media censorship and putting dissenters in brutal work camps.

If Kim dies or is in a vegetative condition, his sister, Kim Yo Jong, is expected to take over. Kim Yo Jong, who is in charge of propaganda affairs, has frequently accompanied her brother on international trips.