North Korean leader Kim Jong-un pays respect to the late former military official Hyon Chol-hae on May 19. (North Korean Central Television).

North Korean leader Kim Jong-un is estimated to be experiencing significant sleep disorders and to weigh around 140 kilograms, lawmakers quoted South Korea's state intelligence agency as saying Wednesday.

Director Kim Kyou-hyun of the National Intelligence Service (NIS) delivered the report during a briefing to the parliamentary intelligence committee, according to key ruling and opposition members of the committee.

"Based on the fact that North Korean authorities have been actively collecting the latest medical information, including medications such as zolpidem, for the treatment of insomnia in high-ranking officials abroad in April, the NIS estimates Chairman Kim is suffering from significant sleep disorders," Rep. Yoo Sang-bum of the ruling People Power Party told reporters after the closed-door briefing.

He said the NIS also stated that it is closely watching the possibility of Kim falling into a vicious circle of depending more on alcohol and nicotine and suffering worsening insomnia as the North has been importing large quantities of foreign cigarettes and high-quality snacks.

The agency also reported "Chairman Kim looked very tired with noticeable dark circles under his eyes during his public appearance on May 16" and an analysis using artificial intelligence of some of his recent photos evaluated his weight to be around 140 kg, Yoo said.

"Since the end of last year, scratches and bruises have continuously been observed on Chairman Kim's hands and arms, which are suspected to be a combination of allergies and stress-induced dermatitis," the lawmaker quoted the NIS director as saying.