According to a South Korean diplomat, Kim Jong Un, the Supreme Leader of North Korea, is in a coma and his sister, Kim Yo Jong, is set to take the nation’s reins.

A former aide to South Korea’s late president Kim Dae-Jung, Chang Song-min, made the sensational revelation to South Korean media, according to the New York Post.

Song-min said that Kim is in a coma, “but his life has not ended.”

“A complete succession structure has not been formed, so Kim Yo Jong is being brought to the fore as the vacuum cannot be maintained for a prolonged period,” he added.

Song-min’s allegation comes a few days after South Korea’s spy agency said Kim had delegated part of his authority to his close aides, including his younger sister, according to the Yonhap News Agency, a South Korean news agency.

Last week, in a private meeting with lawmakers, South Korea’s National Intelligence Service said, “Kim Yo Jong, the first vice department director of the Workers’ Party Central Committee, is steering overall state affairs on the delegation,” though Kim her brother still maintains “absolute authority.”

However, there still are some doubts about the truthfulness of the diplomat’s claims.

This is not the first time that Kim’s prolonged absence has fueled speculation about his health. In April, reports circulated that the 36-year-old leader of the Workers’ Party of Korea had undergone heart surgery after he was not seen for nearly three weeks.

The North Korean government did not explain his absence, including his absence in a commemoration that celebrated the 108th birthday of his late grandfather, North Korea founder Kim Il Sung. However, a South Korean government official told FOX News that the government believes Kim showed no indication of a medical procedure after a video was released showing Kim moving around during the completion of a fertilizer factory near Pyongyang.