Defectors have flown balloons over North Korea with messages from the 'free world', cash, USB drives and SD cards amid claims Kim Jong-un is dead.
Members of a group called Fighters for a Free North Korea released 20 balloons carrying 500,000 leaflets announcing that two high-profile defectors had won seats in South Korea's parliament.
In a new interview, one of the defectors, Ji Seong-ho, said he is "99 per cent" sure that Kim is dead and that the dictator's sister will take control of the country.
The balloons were released in Incheon, close to the border, on Thursday night in the hope that the contents will reach villagers in the North and the messages will spread through the secretive and isolated country.
Fighters for a Free North Korea is an NGO run by North Koreans who managed to escape the oppressive regime.
The leaflets celebrated the election victories of Ji and Thae Yong Ho, who last week told CNN: "I'm not quite sure whether he [Kim] really had some surgery or whatever, but one thing is clear... he cannot stand up by himself or walk properly."
On Friday, Ji said he believes Pyongyang may announce this weekend that the dictator has died and a successor - likely Kim's sister Kim Yo-jong - has been chosen.
Amid unverified claims that Kim was dead, in a vegetative state, "gravely" ill or recovering after undergoing heart surgery, the lawmaker said he was informed that Kim died last weekend after undergoing a cardiovascular operation.
North Korea has held off on confirming its leader's demise and announcing a period of mourning because it is "grappling with a complicated succession issue", he added.
Ji, who won a proportional representation seat in South Korea's elections on April 15, told Yonhap News Agency: "I've wondered how long he could have endured after cardiovascular surgery.
"I've been informed that Kim died last weekend."
He added: "It is not 100 per cent certain, but I can say the possibility is 99 per cent. North Korea is believed to be grappling with a complicated succession issue."
Ji said an announcement could come this weekend and Kim's sister is likely to succeed him.
He did not reveal the source of his information.
Claims about Kim or North Korea's activities are almost impossible to verify due to the country's secrecy and isolation.
Kim, believed to be 36-years-old, hasn't been seen in public since April 11 - almost three weeks ago - when he oversaw a Politburo meeting.
It was claimed he underwent heart surgery the following day.
Satellite images show a train parked at the "leadership station" in the coastal resort of Wonsan for more than a week - suggesting that Kim may be at his luxury compound - but North Korea watchers have cautioned that it could be a diversion tactic.
It has also been suggested that Kim may have left Pyongyang to avoid coronavirus, after people close to him caught the killer bug, and is "alive and well".
South Korea's presidency has insisted that it has not detected any "unusual" signs in North Korea amid speculation about Kim's health and his absence from state media reports.
North Korea's propaganda networks have not mentioned anything about his health or him being absent from public view for weeks, and they continue to report that he is making decisions and sending messages to world leaders.
Kim's 32-year-old sister Kim Yo-jong, who is his closest confidant, his uncle Kim Pyong-il, 65, and his first military chief, Choe Ryong-hae, have been named as possible successors if the current leader is dead or unable to continue.
