On Tuesday, North Korea declared a temporary ban to stop Malaysians there from leaving the country as both countries' ties deteriorated due to a row over the murder of North Korean leader Kim Jong-un's half-brother Kim Jong-nam here.
Taiwanese government sources have said there is no record of Kim Han Sol or his family entering the country, but did not rule out the possibility they may have passed through the country's main airport while in transit.
"My father has been killed a few days ago". In the 40-second YouTube video, the black-clad young man said he is now with his mother and sister, without disclosing their whereabouts.
He signs off by saying: "We hope this gets better soon".
An official at South Korea's National Intelligence Service said the NIS had determined that the man in the video is Kim Han Sol. But, he declined to reveal the process of confirming the man's identity, citing the security and safety of witnesses.
Analysis - North Korea enjoys membership of a small but uncomfortable club with regard to those who annoy the powers that be - instead of throwing you out, they force you to stay.
Kim Han-sol was born in Pyonyang, North Korea, but the 21-year-old has spent most of his life overseas, living mainly in Macau, China, and attending school in France and Bosnia.
"It's right to determine they are the same person", said Lee Cheul-houng, head of the Transcription Analysis Laboratory.
On the morning of 08 March 2017, a short video was broadcast by the Cheollima Civil Defense organisation of a young Korean man speaking in good English.
Kim Jong Nam and his family had been living in exile in Macau, although Kim Han Sol traveled to Europe to attend college. "The Ministry will decide on the next course of action", he said.
In older social media posts uncovered by South Korean media, Kim Han Sol reportedly expressed guilt for having enough to eat while people in North Korea were starving and criticized his family's role in the suffering of the North Korean people. North Korea has denied any responsibility and accused South Korea of being behind the accusation.
"Behind it all, there's Kim Jong-un's desire to solidify his legitimacy as the leader", Japanese new outlets quoted Thae Yong-ho, previously minister at the North Korean Embassy in London, as having said in a meeting with Japanese correspondents in Seoul a day earlier.