Headlines that Kim Jong-un was "gravely ill", "brain-dead" or "recovering from an operation" were always going to be impossible to verify.
But the presidential office in Seoul has said there have been no particular signs from the North to indicate the 36-year-old is "gravely ill".
It is also not the first time rumours about his health have fired up intense flurries of speculation - only to be later dismissed.
Kim Jong-un recently missed the celebration of his grandfather's birthday on 15 April. This is one of the biggest events of the year, marking the birth of the nation's founder.
Kim Jong-un has never missed it - and it seemed very unlikely that he would simply choose not to turn up.
Inevitably, his absence prompted speculation and rumour, none of which is easy to substantiate.
Kim Jong-un last appeared in state media on 12 April "inspecting a pursuit assault plane group" in a handout that is undated. As ever, the images portrayed him as relaxed and at ease.
We know he chaired a key political meeting the day before, from state media despatches. But he has not been seen since.
State media also made no mention of his presence at a reported missile test last week. He is usually pictured at these launches.
Reporting on North Korea is incredibly difficult at the best of times, so most speculation is drawn from departure from precedent.
And now, the already secretive state is an even more extreme version of shutdown - after it closed borders at the end of January due to the Covid-19 pandemic.
The first report of illness
The claim about Kim Jong-un's ill health surfaced in a report for a website run by North Korean defectors on Tuesday.
An anonymous source told the Daily NK that they understood he had been struggling with cardiovascular problems since last August "but it worsened after repeated visits to Mount Paektu".
This led to a chain of reporting by international media on a single-sourced story.
News agencies then began to run with that claim, and it was all they had until some reports emerged that intelligence agencies in South Korea and the US were monitoring the claim.
But then came a more sensational headline in US media that the North Korean leader was in a critical condition after heart surgery.
However, a statement from the South Korean government, and sources at Chinese intelligence - speaking to the Reuters news agency - said this was not true.