South Korea's spy agency said on Sunday that media reports of North Korean leader Kim Jong-un's sister staging a coup against her brother are not true at all.

The National Intelligence Service (NIS) dismissed reports that claimed Kim Yo-jong ousted Kim Jong-un after a coup, reports Yonhap News Agency.

A separate government official also said such reports are not true.

Kim Yo-Jong
Kim Yo Jong, sister of North Korean leader Kim Jong UnReuters

Citing a report from US-based tabloid "Globe", some news outlets here said Kim Yo-jong staged a coup between May 6 and June 5, and removed Kim Jong-un from the post.

The report claimed Kim Jong-un at recent events is actually an impostor, pointing out that his appearance is different than the past, with substantial weight loss.

Kim Jong-un rumours

Speculations about Kim Jong-un's well-being have been brought up by media regularly since last year.

Kim Jong-un

In July, the NIS dismissed rumours over Kim Jong-un's health problems as "groundless".

The North Korean leader earlier this month attended a defence development exhibition in Pyongyang and called for boosting military capabilities.

He was also seen smoking cigarettes with officials at the event, according to photos released by the North.

(With inputs from IANS)